Icon theme

[rodlie]

• [x] generate png's from svg's
• [x] create an hicolor icon theme
• [ ] remove icon loader
• [ ] replace all icons with QIcon::fromTheme

[rodlie]

more work than anticipated... (I need to replace a lot of code) The toolbar is almost done, the rest is blank for now :)

[rodlie]

Close, use #91 to track this issue.