Add ability to run external binary modules

[manoj-freyr]

Til now, RVS runs only modules that are compiled as part of RVS code as shared objects , this module enables us to run pre compiled external binaries via conf file . Can run one module at once via conf now. can modify test-path and test-args .

[jkottiku]

Add new module details in rvs/src/rvsexec.cpp and rvs/src/rvs_interface.cpp as well.