Added profiling tool for MX virtual machine

>> CasadiOptions.startProfiling('prof.log')

$> python -mcasadi.tools.profilereport -o prof.html prof.log
Profiling tool: fixed error in counting calls
Profiling tool: added dotgraph drawing
Enabling profiling for collocation and newton implicit solver
Profiling: refactored the way that profilereports builds up a database
Some work on profiling
Profiling: adding library; attempt to fix for ubuntu 32bit
Profiling: default off
Profiling: add RT library only when it is found
Merge pull request #831 from casadi/profiling

Profiling