Added Nemo Configuration ignoreBrowserCapabilities

For making memo work with the perfecto mobile test suite I needed to add the option to ignore the 'valid browser check' and also disable adding of default capabilities.
PerfectoMobile has its own selenium.jar and is configured via the "serverCaps" option of nemoData config.

To disable the 'valid browser check' configure nemoData like this:
"nemoData": {
    "ignoreBrowserCapabilities": true
}