Update README.md

Minor grammatical/spelling corrections.
Update main.cpp

Minor spelling/grammatical corrections.
Update _ex1.py

Spelling/grammar corrections.
Update _ex3.py

Grammar/spelling corrections.
Update _ex4.py

Spelling/grammatical corrections. (Including the correction Sundmann -> Sundman.)
Merge pull request #5 from NattyBumppo/patch-1

Update README.md
Merge pull request #6 from NattyBumppo/patch-2

Update main.cpp
Merge pull request #7 from NattyBumppo/patch-3

Update _ex1.py
Merge pull request #8 from NattyBumppo/master

More spelling/grammatical corrections
Update closest_distance.h
Merge pull request #9 from darioizzo/master

Barker Equation, sims_flanagan get states, ic2par exposition
Small update on the docstrings
Module description improved
Update documentation.rst
Update documentation.rst
Update documentation.rst