Minor fix in engines doc: elapsed_time -> elapsed_seconds
Merge pull request #89 from dbickson/master

improved svd performance, fixed a bug of missing orthognoalization step
Merge pull request #90 from dbickson/master

fixed svd code to compile
Merge pull request #93 from dbickson/master

fix a documentation bug in using.dox as pointed by jeff zhang
Merge pull request #94 from dbickson/master

added a comment about unnormalized pagerank results
Merge pull request #87 from iglesias/master

Minor fix in engines doc: elapsed_time -> elapsed_seconds
fixed a bug when reading initial vector from file in svd, added prediction support for svd