* added ticking timer feature #54
* updated TT and TT_init files for ticking timer feature #54
Merge branch 'release/0.6.68' into develop
Add CONTRIBUTING guidelines

See also https://github.com/blog/1184-contributing-guidelines
[#54] synchronize ticking sound with timer
[#54] ticking sound on/off checkbox on Timer
Merge branch 'ticking-timer' of github.com:vrybas/tomatoes into vrybas-ticking-timer
Fix coding style; use label element
Add volume and ticking settings

Closes #84

See also #54
bump version number to 0.6.69
Merge branch 'release/0.6.69'