update readme with v0.4.5 informations
replace absolute path with relelink
example Connect TestLink in a python shell added
version set  to v0.4.5
SourceForge Download link added
add long description and categories to setup.py #15
install and usage documentation extracted from readme.md #15

although unit test directory split into two directories

*    utest-offline - unit test not interacting with TestLink
*    utest-online - unit test interacting with TestLink
README format changed to rst, file with release notes added  #15
api methods for platforms #10
createPlatform, getProjectPlatforms
addPlatformToTestPlan,removePlatformFromTestPlan