add if else construct (version 0.0.10)

Patch Set 2: Prepare for use else & blocks
Patch Set 3: adds else statement
Patch Set 4: adds blocks support
Patch Set 5: double if failed, prepare for fix
Patch Set 6: fix for double if
Patch Set 7: fix2 for double if

Change-Id: I26b3f996abc2503fc2a3433cd87a53bc43c788d3
Merge "add if else construct (version 0.0.10)"