New: launch only one test from a classTest

Previously it wasn't possible to launch only one test from a file.
Now OJUnit has this feature, the command to do that is "ojtest NAME_OF_THE_FILE:NAME_OF_THE_TEST"
Fixed: added documentation in the help of the command
New: Added option -E for regex

When launching a test, if the option -E is set, the string after the : will be interpreted as a regex.
Revert "New: Added option -E for regex"

This reverts commit 2df32affed6ee773077852121c4724deff577fa4.
Fixed: removed the arg -E, and use regexp by default.
Merge pull request #25 from Dogild/singleTest

New: launch only one test from a classTest