vim: add support for repeat `.'
stack: <Control><Alt>Page_Up and Page_Down to quickly move documents

This still isn't my preferred way to navigate, but no reason we shouldn't
at least have it in here. We probably should add some context to what
constitutes "previous" and "next" document though.

Right now, that context is widget packing dependent.
build: move c-parse-helper to auto-indent directory
vim: use gtk_source_buffer_change_case()

Removes some custom case changing code in our VIM mode.
vim: try to match resulting cursor position same as vim for toggle case
vim: implement lowercase command

If there is a selection (visual mode) in VIM, u is the lowercase command.
vim: implement toggle undo/redo with `U'

There are probably some semantics I'm missing here. But this gets the
basics working.
vim: implement uppercase with `U' during selection

Like `u', this is a different command when there is a selection. `U' is
uppercase.
build: bump build requirements and simplify cflags/libs
build: Add missing header file

https://bugzilla.gnome.org/show_bug.cgi?id=741899
git: perform repository discovery and blob loading asynchronously

This discovers the repository (which requires a lot of access()) and
loading of the GgitBlob for diff generation in a thread worker.
snippets: make snippet context creation lazy

Should save some memory, string allocations, and make startup faster.
git: avoid hitting disk to render search results.

Previously, we were hitting disk once to get the name of the project
directory and branch shortname.

This caches both when loading the repository.
main: log runtime gtk+ version for debugging
editor-frame: remove unnecessary cast checks
gcc: don't use G_GNUC_CONST for GType functions

It's actually not safe to do this, so we'll just remove the potential
const caching of these type registration functions.
vim: add support for "set et" and "set noet"
git: avoid drawing "add" lines between repository load and blob load
log: remove extra newline
code-assist: avoid extra code assistant calls if service was not found