added convert_to_matrix method in SGVector
fixed some crashes in sparse features unit tests
Merge pull request #1271 from gsomix/feature/linereader

SGVector: convert_to_matrix method
fix c++11 compile error
fixed a memory issue related to uninitialised memory which should be NULL
changed sparse matrix parameter registering
Merge pull request #1274 from karlnapf/develop

Fix segfaults in unit tests
Merge pull request #1272 from van51/develop

Fixed travis warnings for implicit conversion from NULL to bool
add CSGObject as supported serialization PT
Changed behavior in Hashed numerical classes