Replace doc_array with documents_array, a pointer array. This is
necessary to avoid breaking the ABI every time a field is added to
GeanyDocument.
Remove deprecated pluginmacros.h documents macro, to avoid a
conflict.
Replace doc_list[] macro with documents[] macro, which returns a
GeanyDocument pointer.


git-svn-id: https://geany.svn.sourceforge.net/svnroot/geany/trunk@2624 ea778897-0a13-0410-b9d1-a72fbfd435f5