Switched the unit test for any neighborhood preserving DR method from testing Locally Linear Embedding method to testing Isomap (since LLE seems to be not very robust to noise).
Fixed missing #include's in test Isomap_unittest.cc.
Merge pull request #1016 from vladislav-horbatiuk/lleTest-fix

Switched the unit test for any neighborhood preserving DR method from sting Locally Linear Embedding method to testing Isomap.