Update synchronize.rb

Threadsafe timeout at SynchronizePrimitive#enter
Merge pull request #59 from AtoxIO/master

Better timeout checking in synchronize.rb
lmdb works only on 1.9 and 2.0 currently
improve specs
Merge branch 'master' of github.com:minad/moneta
fix benchmarks
improve specs: check empty values and keys
mdb was renamed to lmdb
Merge branch 'master' into staging

Conflicts:
	script/benchmarks
	script/generate-specs
minor improvements
try to hack on the git interface