updated namespace of Pg backend
Merge all staging hooks to staging specific loader role
Merge the merge_ontology hook to Ontology loader module
Added create and update synonym method to Pg backend role
fixed conflict
Added pg_schema option to both the obo loaders
Added support for loading to a particular schema
added schema namespace
added temp table for pg backend to hold comments
added support for loading in temporary table
Removed method hooks, instead put the dependent method names to be
picked up from the attributes
Add ontology_namespace method in the loader. It uses the ontology
idspace in case default namespace is not set
persist new comments for SQLite backend
refactored all sql to a separate lib file
Fixed issue with synonym column and reporting of loader
Fixed issue with synonym column and reporting of loader
added support for updating comments(broken though) and loading of sqllib
Updating comments works for sqlite backend
Caching of existing cvterms is now done before it is updated
The update step reuses the existing cvterm  table
Merge branch 'refactor/sql-handling' into tmprebase
fixed the issue with temp synonym table was not getting populated
Add sql library for pg backend
Added pg backend support for loading comment
Added where clause with type_id when deleting entries in cvtermprop and
cvtermsynonym tables
Fixed syntax errors
Added back the synonym insert statement for Pg backend
Merge pull request #70 from dictyBase/feature/obo-comment

Feature to load comments from ontology OBO file