Merge pull request #132 from skydb/table-object-keys

Add GET /tables/:name/keys.
Fix cursor close after key retrieval.
Add factor variable association.
Add session loop.
Merge pull request #133 from skydb/session-loop

Add session loop.
Fix quote escapes in SkyQL.
Merge pull request #135 from skydb/fix-skyql-quotes

Fix quote escapes in SkyQL.
Use read-only LMDB transactions to allow parallel querying per servlet
Fix cursor error reporting.
Merge branch 'unstable' of git://github.com/skydb/sky into unstable
Avoid abort on readonly transaction as it clears open DBIs
do not pass mdb.CREATE when transaction is readonly
Merge pull request #136 from boourns/unstable

Use read-only LMDB transactions to allow parallel querying per servlet
Add optional ampersand on variable names.
Refactor ampersand variable naming.
Merge pull request #137 from skydb/skyql-ampersand

Add optional ampersand on variable names.
Add average (mean) to available aggregations.