Add some references and change data structure.

Now some papers related with PCx are pointed in for the developers
and for the examples of Fortran's data structure are used gdb style
and provide a script.

TODO: Add the C data structure and others from Fortran.
Add a new reference.
Add time limit to bench.

PCx have a option to limite the duration of the search for the
solution. To have this option in the benchmark will need to
update the benchmark script to Python 3.3.1 or high and use the
subprocess class.

Some improves in the documentation of the benchmark script have
been done and the solution process of the current process file
are save in a file.
Correct bug with log name file.

When add the flag -s at the PCx calling a bug have been introduce
because when using this flag the log file always have the name
-s.log.

This commit correct this bug the calling with the -s flag write
the log in the default file.
Add new parameter to bench.py
Correct "bug" in the return code.

For some problems Interior Points Methods have problems in the
convergence and fail.

For this problems the Solution->Status set up in the function PCx can
get news user in trouble because a conflict with the return code of
PCx program. In this commit we change the Solution->Status and the
return code of PCx program to be compatible.
Correct some bugs in `bench.py`.

In this commit some bugs in the regex of the bench.py have been
correct.

The number of information retrieve have increase.
Corrections in the Makefile
Write function for find connect component

Write function for find connect component for the RCM algorithm.
Some improves at rcm.

The rcm function have a bug from the order_by_degree().

The ppnf() wasn't write yet.
Trying to write the correct output.
PCx with RCM run witout problem for one problem.
Write PPNF.

In this commit the function ppnf was write.

It still have to be tested and bugs removed.
Correct some bugs in PPNF.
Add reverse order for RCM.
Remove old file.

Em upgrading the compilation script a old file haven't been
removed.
Improve bench.py based on test library

Some modifications in the bench.py was done to it be capeble to
test only one library.
Correct little bug at bench.py

The flag for crescent and decrescent order are wrong. This commit
correct that.
Replace Bubble sort with Heap sort

In this commit a heap sort have been implemented and it replace
the bubble sort used in rcm.
Solve bug when rub bench.py for Meszaros library

The parameter `g` of the `bench` function at bench.py must be a list.