Make sure GDK_MOD2_MASK is cleared when getting modifiers.

gtk_accelerator_get_default_mod_mask() behaves differently on OS X under
GTK 3 when compared to GTK 2. On GTK 2 it used to clear the GDK_MOD2_MASK
bit while on GTK 3 it's preserved. We need to clear it ourselves
otherwise e.g. <Command>S leads to <Commands><Mod2>S and none of the
keybindings work under GTK 3.

* Try non-symlinked VTE libraries on macOS before the symlinked ones

Plugins using VTE such as multiterm or debugger are linked against the
non-symlinked version of the library like libvte.9.dylib and not
libvte.dylib. When a bundle is created, all symlinks are replaced by
a copy of the symlinked file. This means there are both libvte.dylib
and libvte.9.dylib in the bundle both containing the same code. When
Geany loads libvte.dylib and plugins load libvte.9.dylib the same code
gets loaded twice and when the same type gets registered by GTK, it fails
and the whole application freezes.

This problem doesn't exist on linux or when running from the command line
on macOS because the operating system detects it's the same library
because of the symlink and it's loaded only once.

Loading the same library as the one used by plugins fixes the issue with
macOS bundle. The original symlinked name is still used as a fallback.

The patch also adds #ifdef __APPLE__ around the Apple-specific library
names which also prevents unnecessary retries on other platforms. Loading
*.so libraries is still kept as a fallback on Apple as these are legal too
and could in theory be used on OS X as well.

* Try loading newer VTE versions before older ones on GTK 2

Closes #904

Closes #1589

Mention G_GNUC_UNUSED as an alternative to `-Wno-unused-parameter`.

exampe openbsd.

This will allow the compiler to notify any callers that it's deprecated.
The macro is guarded-out for when Geany is compiling so it won't cause
warnings when tagmanager uses it internally and for the utils_ wrapper.

This is a wrapper around tm_get_real_path() but is in a more suitable
namespace/module.

Now that a new enough GLib is available the signal can be
handled cleanly on the main loop using the GSource for Unix signals.
This replaces the illegal SIGTERM handling that was disabled in
fbb89f52.

Closes #1255

Closes #1282

Similar to applications like Firefox and Chromium.

This behavior might be unwanted when changing project settings which
is unrelated to project base path and also fixes filebrowser behavior
with the updated way project-save signal is emitted.

The patch also handles the situation where "realized" is called after
project-save is called and overrides file browser's path (which is
something we don't want).

For some reason "project-save" isn't emitted when closing project - see
write_config(FALSE) in project_close(). This means that in this case
plugins cannot save their configuration into the config file. This doesn't
even correspond to the documentation of the signal

"Sent when a project is saved (happens when the project is created, the
 properties dialog is closed or Geany is exited)"

as the signal isn't emitted when exiting Geany because at this point Geany
closes the project.

The comment seems to indicate that the reason is that "project-save"
shouldn't be emitted when "project-close" is emitted but I don't see any
reason why.

Bump API so plugins can rely on the changed behavior.

Increment one time for both, and fix the corresponding doc comments.
The comment for keybindings_load_keyfile() is reflowed to split into
brief/detail sections properly.

size, but optionally not both.

This allows plugins to reload keybindings later during their execution.
For more info see the comment in the commit.

Closes #1430

This indicates that TMTag is GBoxed-derived, and can be copied/ref'd.

This helps plugins that must store a tag pointer for later usage while the
tagmanager might let it go in the meantime (can happen quickly if the user
comments a function out when starting a doxygen-comment).

Closes #1465

In the future, this could be moved to release-mode runtime errors which
try and pop-up a dialog message and/or recover gracefully.

Since filedef config files are now stored under the "filedef" subdirectory
of app->datadir, we need to add the subdirectory name when creating path
from the corresponding app->configdir otherwise the file isn't found.

Closes #1482

fix the issue that candidate window can't follow cursor.

Closes #1514

* Add missing string and comment styles for various lexers

A bunch of string and comment styles were missing and so Geany could not
detect the corresponding styles in code.

* Add more string styles

* Add regex styles as string styles

Do not allow more than one plugin manager dialog at a time.  It doesn't
make sense and the code is not fully re-entrant and leads to a crash
toggling plugins in both dialogs.

Fixes #1563.

The variable used for setting the cursor isn't used anymore and
was used uninitialized. It's simply deleted now and the correct var is used.

This was only a problem if editor_insert_text_block() was used directly,
the snippet code path doesn't reach to it.