Enforce coding style

[DanielGuramulta]

Enforce coding style on commits.

To prevent files mixing different coding styles

// example
if () {
    ...
}

if() {
    ...
}

we make Travis check the style of the files, being edited(patched) in the commit(commit range), and if something is not formatted according to the .clang-format files specifications, we fail the build.

For this to go through, we need:

1. to discuss the coding style and code it into .clang-format
2. format the existing code
3. remove the test commit a3bc159

[commodo]

Some commits could use some descriptions

[commodo]

commits could use a description