Add debug mode for browser

Browser can be launched with -debugMode argument. When launching
in debug mode an overlay is drawn on top web content.

Currently debug mode only contains content height, content width,
scale, and a button for dumping memory snapshot.

Requires: https://github.com/tmeshkova/embedlite-components/pull/56
Add command line argument for dumping memory info
Coding style improvements
Merge pull request #143 from rainemak/debugMode

Add command line debug mode support for browser