Spelling corrections

Basically correcting all instances of the expression "bellow", replacing
them with "below"
Merge pull request #3 from caparicajr/master

Grammar Nazi arrives! Basically correcting all instances of the expression 'bellow', replacing
them with 'below'
Change 'geophysical' for 'geophysics'. Better for search
Adding new ideas in TODO
Merge pull request #7 from hbueno/devel

Adding new ideas in TODO
Removed unused deprecated matplotlib import nxutils
Merge branch 'master' into devel
Removed TODO file and ported all notes to Github issues
Set blit=False in seismic wave recipe
Merge pull request #20 from hbueno/master

Set blit=False in seismic wave recipe
gzz function on sphere.py
cookbook gzz function and corrected from SI2EOTVOS import error
Merge pull request #24 from birocoles/devel

gzz function on sphere.py
Updated copyright notice in docs
Merge branch 'devel' of github.com:leouieda/fatiando into devel
Merge pull request #26 from leouieda/devel

Getting rid of devel branch
Added Andre to contributor list
loading segy tools

Adding psegy.py with class for open segy files and trace.py with classs
to manipulate traces. Probably will be joined soon. First commit for
Caparica code.
Many changes in trace class.
Created a new class segy using a modified version of trace class.
Everything is nested also using "with" to avoid problems with huge segy
files.
segy reading working

Tested with marmousi shot and file from caparica. Working fine.

+ Need to extend functionalities to cover writing files too.
+ Need to write demo codes (cookbook).
+ Need to include suxwigb/image functionalities (port from existent
caparicas)