Minor: improved exception on sql parsing
Fixed issue #2630
Fixed pom.xml issue with distributed sub-project
Fixed issue #2639
Fixed concurrency problem during server startup
Issue #2640 was fixed.
Fixed issue #2643
Merge pull request #2645 from fabriziofortino/develop

stats: percentile and median impl + minor refactoring to mode
Merge pull request #2648 from fabriziofortino/develop

percentile function now accepts more than one quantile
Issue #1611 Bug with removal of cold pages was fixed.
Merge remote-tracking branch 'origin/develop' into develop
Issue #2632 was fixed.
Issue #2632 was fixed.
(cherry picked from commit 7830a4d)
refactored custom string serialization for be complaint to utf8. issue #2636
add speed test for integer and varint seriliazation
implemented simple a storage performace test.
fixed document reset wrongly run deserialize
Merge branch '1.7.8' of github.com:orientechnologies/orientdb into 1.7.8
Issue #2640 - binary compatibility issue was fixed.
Merge branch '1.7.8' into develop

Conflicts:
	core/src/main/java/com/orientechnologies/orient/core/storage/impl/local/paginated/base/ODurablePage.java
	tests/src/test/java/com/orientechnologies/orient/test/database/auto/SQLUpdateTest.java