Markdown: Add support for GTK3
Autotools: define GP_GTK3 as an AM conditional

This allows plugins to have conditionals in their Makefiles depending
on whether they are built against GTK2 or GTK3.
Autotools: honor --with-geany-libdir when checking whether to enable GTK3
GeanyGenDoc: fix a memory leak when saving the configuration
spellcheck: Fix check for default language if LANG contains UTF-8

g_strndup() copies bytes, not UTF-8 characters.
Merge branch 'master' of github.com:geany/geany-plugins
GeanyMiniScript: make the plugin compile against GTK3
Merge pull request #97 from earshinov/geanyminiscript-gtk3

GeanyMiniScript: make the plugin compile against GTK3
GProject: Fix GTK+3 support

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
Focus the file view when switching to sidebar using the keyboard

Thanks to Giuseppe Corbelli.
Remove unnecessary assert
Fix box inclusion order
New plugin: Pair Tag Highlighter

The plugin finds and highlights matching opening/closing
HTML tag by clicking or moving cursor inside a tag.
geanyinsertnum - compatibility with gtk+ 3
Extending HACKING-file with some information about e.g. build system (autotools)
Merge pull request #99 from vmkononenko/pairtaghighlighter

New plugin: Pair Tag Highlighter
Adding pairtaghighlighter to MAINTAINERS-file
Adding pairtaghighlighter plugin to list of translatable files
Improve GP_ARG_DISABLE() default to auto inside HACKING
TreeBrowser: Fix GTK+3 support

Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>