Merge pull request #69 from Gaerzi/master

Sync with my fork.
- Increased grid status bar section width to fix #63
- Added splash+progress stuff when opening maps
Merge branch 'master' of https://github.com/sirjuddington/SLADE.git
Added tab style to interface prefs panel.
Merge branch 'master' of https://github.com/sirjuddington/SLADE