Changes to generex to match Maven structure

This is pull request for Generex library changes to match Maven structure. The updates include:
1) Maven script to build deploy and publish Generex library to Sonatype Nexus
2) Code cleanup to fit Checkstyle, PMD, FindBugs rules
Currently it publishes releases under com.github.mkolisnyk group. This is done just because I can access it as I need some releases but if those changes are of interest the group can be changed to whatever is appropriate.