Convert 'map' table to 'Mapping' and use NCBI for updates.

Convert the 'hg18.map' and 'hg19.map' tables are to 'hg18.Mapping' and
'hg19.Mapping'. These tables are now updated with mapping info from the
NCBI instead of the UCSC.

Also added database and configuration file migration scripts.

extras/config.example:
- Remove configuration values for UCSC updates.

extras/post-install.sh:
mutalyzer/Mapper.py:
mutalyzer/Db.py:
- Use 'Mapping' table instead of 'map' table.

extras/cron.d/mutalyzer-mapping-update:
mutalyzer/Mapper.py:
mutalyzer/Db.py:
- Get mapping updates from the NCBI.

extras/migrations:
extras/post-upgrade.sh:
- Automated migration scripts.



git-svn-id: https://humgenprojects.lumc.nl/svn/mutalyzer/branches/refactor-mutalyzer-branch@342 eb6bd6ab-9ccd-42b9-aceb-e2899b4a52f1