[NSM GDrive] migrate to Util::MimeDetector (fix #1466)
[Popishu] Added missing breaks.
[Popishu] Avoid std::auto_ptr.
[Popishu] Use enum classes.
[Azoth] Remember last file path in file send, closes #1505.
[Azoth] Use home path instead of PWD.
[Popishu] Removed unused function.
[Popishu] Open is now a QToolButton with recent menu.
[Popishu] Removed "File" window menu.
[Popishu] Read from the file via QScintilla means.
[Popishu] Refactored stuff to SetupDefPairs().
[Popishu] Got rid of window menus at all.
[LMP] Fix segfault on empty collection in dynamic playlists.
[LHTR] Added enum for tab indices.
[LHTR] Only sync to HTML if current page is not HTML edit.

Fixes #1508.
[LHTR] Added basic HTML highlighter.
[LHTR] Added HTML attr name/value highlighting.
[LHTR] Instantiate highlighter.
[LHTR] Missing break.
[LHTR] Fixed tag ending.