Updated ImageButton to have rollover images instead of pressed images

Signed-off-by: Dalton Pelc <daltonjpelc@gmail.com>
Renamed 'Spoutcraft' to 'mod pack' and renamed 'Spoutcraft Launcher'
Added new hover icons
Refactored InstalledPack/PackButton/ModpackSelector for further clean
code and direction towards custom modpacks

Signed-off-by: Dalton Pelc <daltonjpelc@gmail.com>
Scroll wheel on your mouse now lets you scroll packs

Signed-off-by: Dalton Pelc <daltonjpelc@gmail.com>
Merge pull request #72 from vidplace7/dev

Renamed 'Spoutcraft' to 'mod pack' and renamed 'Spoutcraft Launcher'
Fixed mirror URL