Merge pull request #92 from daron1337/pt

added vmtkmeshmergetimesteps, vmtkparticletracer and vmtkpathlineanimato...
Handle degenerate bifurcation case. Many thanks to Pieter Kitslaar for
the hint, https://github.com/pkitslaar/vmtk/commit/167200c063c65813a7c4fc07f232474a8ff683ad
Remove spurious numpy import
Merge pull request #93 from lantiga/master

Fixed handling degenerate bifurcation case in bifurcation reference systems. Thanks to Pieter Kitslaar for the hint.
Explicit initialization for previousEdge2 variable and check on number of iterations

previousEdge2 variable was not initialized (caused Run-Time warning in Visual Studio).
Added explicit initialization and helper variable for number of
iterations to only check previous edges after initial iteration.
Added check that all TargetSeedIds are found.
Merge pull request #94 from lantiga/master

Pulling Pieter Kitslaar's commits. Thanks!
Merge pull request #96 from daron1337/pt

vmtkparticletracer bug fix and vmtkmeshmergetimesteps improved
Merge pull request #97 from daron1337/pt

fixed timesteps data field in vmtkmeshmergetimesteps and vmtkparticletracer and arrayMax in vmtkpathlineanimator
Merge pull request #98 from daron1337/pt

New script vmtkmeshextractpoint data and small fixes on vmtkmeshmergetimesteps and vmtkparticletracer
Merge pull request #99 from daron1337/pt

vmtkmeshextractpointdata
fixed vmtkmeshviewer2