Enhance Installation, Icons, Path, Comments, Indentations.

Still need to update new icons.
Waiting for Shlomi.

Signed-off-by: Meir <Meirtz4@gmail.com>
Set About and update share text
Enhance Icons
Add Exit button
Fix About and Share for API < 11
Fix if previousPage=null when clicking back
Added\Updated missing categories
Fix Medicine and Chronology categories
Update version to 2.1