New features:
- The game view can be scaled using the "pinch" gesture.

Bug fixes:
- Corrected available chip types and number of waves for stages 22 and 32
- Made the outline around active MEM chips more recognizable (issue #233).
- Graphical stage layout tended to be rather elongated on large devices.

Miscellaneous:
- Heroes to go on holiday must be re-selected each time a leave level is entered (issue #210).

