Issue #1404 Durability test which checks that after restore DB can be used without any issues was added.
Issue #1404 Shadow copy of paginated cluster state was implemented.
Issue #1404 Record creation crash test was passed.
Issue #1404  Document update crash tests were passed.
Issue #1404  Document update+create+delete crash test was passed.
Issue #1404  WAL performance improvements.
Issue #1404  Crash test with creation of big data records with small cache size was passed.
Issue #1404  Storage keep open is set to true by default for embedded DB.
Merge remote-tracking branch 'origin/develop' into plocal-crash-test

Conflicts:
	core/src/main/java/com/orientechnologies/orient/core/config/OGlobalConfiguration.java
	graphdb/src/test/java/com/orientechnologies/orient/graph/blueprints/RemoteGremlinTest.java
Issue #1404 Import/export functionality was restored.
Issue #1404 WAL durability during power failure was improved.
Update README.md
Issue #1404 New paginated cluster attributes were added.
Created 2 test for distrib execution using local and remote protocols
MInor: added a check in ODocument to avoid wrong settings of multiple parameters
Distributed: improved management of alignment request
Fixed bug on creating edges with no class
Distributed: fixed aligning problems
Distributed: fixed bug on propagating commands among the cluster nodes
Replication: fixed synchronization problem on massive load