PhaseBeam: Tri-phase the electron beam

This commit fixes Google's derps in PhaseBeam wallpaper:
- The wallpaper is now smoother
- The bounds of the particles are fixed
- The wallpaper now have a nice scroll animation when
  you scroll wallpapers. Google disabled this because
  originally, the wallpaper only updates every 66ms. This
  caused the WP to be super laggy when scrolling. To
  circumvent this issue without melting your battery
  down, we offer a nice speed bump when the user is
  scrolling, so he doesn't notice that the wallpaper
  isn't updating at 30 fps (60 fps only when scrolling).

Change-Id: I69ae83fa454890aec5269dafae112057b88be2ab
PhaseBeam: Allow color customization

PhaseBeam now has a Settings screen, and sliding
your finger lets you choose your color. Tap the screen
to reset to default color.

Change-Id: Ibb11ef42ecca040ae172b4e44597205ca263d869
PhaseBeam: Fix color not restoring on reboot

Change-Id: Icd28671791845c9667b60bc5fd6e445ade4fd39e
PhaseBeamSelector: Make license of that file clearer

- Brings back license of the original unmodified file
- GPLv3 applies only to the changes made by myself in
  the previous commits to this file

Change-Id: Iafe166c8836da5f86b7c166518f5e6c84fc8dbac