Refactored KeyListOps, Context, mapFile to make KeyListOps reusable by other tools

Created new KeyListOps class to replace vectorOps. Converted map tool to...

Update related-tools.rst with intersphinx

Added to "related tools", seemed the most appropriate place for now.

Update installation.rst

added macports as an option for installing bedtools on mac os x.

Intersphinx

* capability

Refactored contexts for validation, added unit tests, enabled -plit for ...

typo on option -useFullHeader