implement Path.getName(int i)

- boundaries test still not written but in TODO
fix test : empty path not allowed

-> in such case we should probably use current directory as fallback
cleanup comment
implement & test boundary conditions on getName

+ use static method for easier MemoryPath creation in test
conde formatting
wip : memory path impl + tests
equals & hashcode basic test
fix equals & hashcode + test
add toString() impl
equals & hashcode systematic test
code format
cleanup
check uri validity just after creation
implement getParent()
fix getName & its tests
fix createPath : direct path comparison is not doable yet
getFileName() test
move static test code to bottom + fix varargs warn
implement toAbsolutePath and fix relative toUri

- toUri for a relative URI has no real meaning, thus we tranform it to absolute path before URI generation