Split GeanyFunctions out of GeanyData so data pointers can be
appended before the function pointer structs without breaking the
ABI.
Rename GeanyFunctions fields with a p_ prefix to avoid name
conflicts.
Add new plugin symbol geany_functions.
Nearly all plugins will now need to declare the following:
'GeanyFunctions *geany_functions;', which is now used by
pluginmacros.h.
Add doxygen examples for geany_data and geany_functions.
Move deprecated document and filetype typedefs to src/plugindata.h,
as plugins aren't required to use pluginmacros.h.
Initialize geany_data by copying a stack struct so the compiler can
check for any missing field initializers.
Rename plugin macro p_encoding to p_encodings to follow the core
function encodings_ prefix.


git-svn-id: https://geany.svn.sourceforge.net/svnroot/geany/trunk@2599 ea778897-0a13-0410-b9d1-a72fbfd435f5