Addition of the README and basic Groovy source samples.

- Addition of the README.txt file explaining what this repository is all about.
- Addition of Groovy sample source.
- Addition of sample resource Properties file.
Added sqaring method
Refactored squaring into a separate class
Ignored *.class files
Added shell script to drive the execution of the app
Added sum function and test call
Removed unused Square class import
Used static imports to simpify the math calls
Added call and import for subtraction
Added subtract feature
Removing subtraction from the division line of code
Merge branches 'feature_division_polished' and 'feature_subtraction_polished'

Conflicts:
	src/Main.groovy
	Solved by bringing in both features (both imports, both calls)
Added text about image diff example
Adding log files and build output to ignore
.gitattributes to make this play nicely onWindows
Adding maven build script
Added gradle build file
Fixes #1
Travis CI
Even I can change the readme file