Add rbgs.c

Add Simple program parallel.
Add function to check parameters.
Add function to print parameters.
Add struct malha.
Add function to create 'grade'.
Add function to print 'grade'.
Add function to calculate f(x,y) = 4*(PI^2)*sin(2*PI*x)*sinh(2*PI*y).
Add functions to calculate values of boundaries.

Signed-off-by: Gustavo Toshi Komura <gtk10@c3sl.ufpr.br>