Improve touch event handling to support resize on android too

Signed-off-by: scripple <github@scripple.org>

Touch resize doesn't work on android (4.4 at least) or in the chrome mobile emulator.  This fixes that and according to a tester still works fine on ios.

Second attempt due to variable declaration issues in first one.

Submitted in response to https://github.com/samclarke/SCEditor/issues/290