Add generation of ext-timezones.json

:Release Notes:
Made ext-timezones.json generated from available tzdata

:Detailed Notes:
- extracted out reference information Description/City/preference into
  uiTzInfo.json which is used for generation
- extracted out reference information about MCC into mccInfo.json which
  is used for generation
- added abbrevs.py which contains description of time-zone abbreviations
- added extract-description.py for automatic extraction of UI related
  info
- gen-ext-timezones.py generates ext-timezones.json

:Testing Performed:
desktop build and qemux86

:QA Notes:

:Issues Addressed:
[BHV-810] Find better way for obtaining time-zones in luna-sysservice

Open-webOS-DCO-1.0-Signed-off-by: Nikolay Orliuk <nikolay.orliuk@lge.com>

Change-Id: Ie10a301fa3be8234bdef1a70f33960274f6a26eb
Reviewed-on: https://g2g.palm.com/4688
Reviewed-by: DCO Verification
Reviewed-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Tested-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Reviewed-by: Anatolii Sakhnik <anatolii.sakhnik@lge.com>