Add new method operator and rewriting Short.
Added operations to Fractions.
Merge pull request #2 from Diego2la/GitRuS

Git ru s
Fix add space to code
Merge remote-tracking branch 'origin/master'
Add Test for Fraction. Short doesn't work.
Merge remote-tracking branch 'Diego/master' into Diego

Conflicts:
	src/structures/Fraction.java
modification in tests