Merge tikz and matplotlib

This PR close #9 since it has been supersede.

The flag for semilog plot in issue #11 has been add.

Some others changes:

* The arguments for `__init__` of PerProfSetup is now just args
  (from argparse)
* Add option for logarithmic scale
* Add options for matplotlib and LaTeX/TikZ (they are exclusive)
* Create module for LaTeX/TikZ plot function
* Move examples from `tikzexample` to `test`
* Remove `tikzexample/profile.tex` since it was the output of this
  module
* Remove `tikzexample/examples.tex` since the user must know how
  to write it.

TODO:

* Add function to write the main document for the LaTeX/TikZ
* Implement the logarithmic scale option for matplotlib