Api changes :
- removeLastPathElement do not takes extra arguments
`removePreSeparator` and `removePostSeparator`.
This is not needed as path do not need special tailing separator.
- Only one function `split`. Arguments can be implicitly convert to
string. No need for overloading functions to explicitly cast them.
- `split` function takes another argument `trimEmpty`. If true, empty
element are removed.
Path manipulation now almost pass trough a vector<string> to store each
path's part.
Most of the complex works is now made in the normalizeParts function.
Matthieu Gautier