When mac integration or binary relocation are disabled, the compiled
object file contains no symbols because the guards in the source files
hide all code. On OS X there's a warning during compilation saying:

/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/ranlib:
file: .libs/libgeany.a(libgeany_la-prefix.o) has no symbols

If these features are disabled, don't compile the corresponding
sources to avoid the warnings.

Interestingly, waf compilation works without warnings - it appears
linking is done through g++ which doesn't produce these warnings.

This is useful for plugins to be able to subclass the ScintillaObject
and use its full GObject features. The Overview plugin is one known
plugin that needs this.

Also update scintilla_changes.patch by running update-scintilla.sh
script with patch application commented-out and generating a reverse
diff using `git -R`, and manually remove `a/` and `b/` prefixes from
the resulting diff so it can be used with update-scintilla.sh script.

This merges PR#429 with only small history cleanup (no code changes),
and ABI bump.

Closes #355, #358 and #429.

Instead of abusing static libraries putting shared objects in them, and
manually setting the flags required to build shared objects, use sets
of objects and Waf's own cshlib/cxxshlib flags.

Also explicitly call the appropriate build context method instead of
only listing features in order to make it clear what is built.

Some references:
* http://docs.waf.googlecode.com/git/book_16/single.html#_predefined_task_generators
* http://docs.waf.googlecode.com/git/book_16/single.html#_local_libraries
* https://code.google.com/p/waf/issues/detail?id=1398

geanyfunctions.h used to bring all function declarations, and some
plugins depend on this side effect instead of properly including
geanyplugin.h directly.  So, reintroduce the behavior for
compatibility with those plugins.

This avoids breaking plugins that don't use geanyplugin.h as they
should but include some random headers.

Whether rpath is liked or not, it allows geany to Just Work and is consistent
with autotools

The -fvisibility=hidden flag for libgeany.so is also applied to plugins.
This is not desirable.

- libgeany install dir was wrong on win32
- comdlg32 is required
- more headers need to be installed
- -fPIC is required on some platforms
- LINKFLAGS_cprogram now have to be applied to libgeany.dll

There is no need for tricking Automake to use the C++ linker to link
the main executable anymore, this is done for libgeany now.

Based on previous work from Matthew Brush.

4.2BSD sed doesn't understand the `+` quantifier, so use `{1,}`.

Instead of processing a template C source in the build system, generate
a list to be included by the preprocessor.

This simplifies the build system code as it now only generates the list
and doesn't take care of processing the template.  It incidentally
fixes build on systems with 4.2BSD sed (at least OSX and FreeBSD) as it
removes some offending sed code.

It includes stuff like -fvisibility which isn't appropriate for the main binary.

This is a bit better than compiler == 'gcc'.
Tested with gcc 4.9 (success) and gcc 3.4.5 (not supported).

In Waf, we need to add the new flags to CFLAGS *and* CXXFLAGS otherwise
the Scintilla build would break.
To keep it more reabable, we first populate a temporary list
geany_symbol_flags which is then added to CFLAGS and CXXFLAGS.

Concerning the quote FIXME: no further qoting is necessary here.

This makes it easier to define it consistently to what the compiler
and platform supports, and avoids having to include a special header
everywhere, which is some kind of a problem for separate libraries
like TagManager and especially Scintilla.

As we only use these macros from the source and not the headers, it
is fine for it to be defined to a configure-time check from the build
system.

Warning: Although Waf and Windows makefiles are updated they are not
         tested an will probably required tuning.

Use the same variable style for simple interpolations ("$foo") than for
complex ones ("${foo}") instead of using the string style itself.  This
gives a visual feedback for simple interpolations.

Zephir filetype

Implement Erlang ctags

... so the tags will appear in Geany.

Use consistent shadows across Geany