Improves web-service performance.

This allows various rather static responses to be cached, substantially
lightening server load and improving page response time.
Added test for etag filter
Add comments
Lowered log level
Merge remote-tracking branch 'upstream/beta' into beta
Use Hikari Connection Pool instead of Postgres default, currently properties hacked around.
Replace ObjectStoreWriter connection if it has been closed somehow.
Read properties for HikariCP connection pool, alter access to underlying PGConnection.
Update database connection properties for new connection pool.
Fix casting to PGConnection.
Export postgres jar.
Close the connection pool correctly.
Less log output of ids.
Extend timeout when checking connection is still valid to avoid build errors.
Merge branch 'beta' of github.com:intermine/intermine into cachier-models

Conflicts:
	intermine/web/main/src/org/intermine/web/filters/ReleaseEtagFilter.java
Merge pull request #669 from alexkalderimis/cachier-models

Improves web-service performance.
Bouncy-castle provider for generating certificates.

Used in tests to make sure we can consume JWTs correctly.
Type saferer ast
checkstyle
Fixed up eclipse project definitions.