added the 3 new files for the arclength reparametrization

assembled the system, now we are doing the solver.

we need to create a proper test for our utility

Up and running the test for the length of the curve
The tests seem to be working properly
Trying to make travis happy.

Added blas.

Fixed typo on .travis

Trying another .travis script.

Yet another attempt to fix.

Yet another attempt to fix. v2.

.travis fixed. Now making it better.
found bug in test
the test on the arclength is not testing anything
pippo
reshaping all the arclength utility
improving the reparametrization
ready for testing with multicomp vecspaces
removed the conflict
now LS works with matrices as rhs
found the bug, now it is time to test it properly
added an example and testing
fized the reparametrization and the tests
changed the name
com
solved a bug i put in lag vect space
Merge pull request #22 from nicola-giuliani/arclength

Arclength