Removed Percolator part

Can"t finally understand how it should work, removed it for now (only using first index, use of _percolator as type name...)
Enabling LocalMode + fix date parsing

Date are converted as ISO8601 both ways
Started tooling of response parsing
Reimported tests

Rolled back Gson for parsing object to use Indexable#fromMap solution
Fix java-sample
Changed artifact coordinate

Coordinate set to -jest to allow proper usage in in-house projects
Refactored client setup a bit

Cleaned up the mess I've made
Moved Jest into proper package

Moved everything related to jest in a proper package
Cleaned up the code

IDEA inspections clean up :
 - fix potential NPE
 - added @Nullable/@NotNull
Renamed jestXcute to execute

Proper action naming
Changed execute to be callable in JestRequest

JestRequest can call execute directly
Requests now returns JestRichResult

To be able to return more cleanly rich results, we now return JestRichResult which provides convenience method and delegate "classic" jestResult method to the underlying object (in a safe way)