Introduced a folder for developer skins
cleared developer_skins folder
Added res/developer_skins as submodul
Insert a colon (fix)
Add ToolTipRole for sidebarmodel (currently broken)
Display a tooltip only when the node is not a root
Perform a type check before casting to TreeItem*
Display the name for the Quick Links node
fix modplug support

Fix build error due to passing a const pointer to modplug read function.
Fix UI baseclass (QWidget instead of QDialog)
Fix UI size behavior for ModPlug Decoder Preferences.
Remove superfluous tabstops that were giving warnings.

Signed-off-by: Stefan Nuernberger <kabelfrickler@gmail.com>
Add two QString members to remember the last used directories
Remember the last directories used for importing and exporting playlists
Merge pull request #159 from snue/feature/modplug

fix modplug support
Merge pull request #158 from badescunicu/sidebar_tooltips

Sidebar tooltips [Bug #1017034]
Use the same last directory for both import and export playlist
Store the last import/export playlist directory across Mixxx restarts
Store the last import/export crate directory across Mixxx restarts
Merge pull request #160 from badescunicu/remember_playlist

Remembering last playlist directory Bug #1178782
Merge pull request #155 from daschuer/developer_skins

Introduced a folder for developer skins