Fixes #1934
Convert to Poco::URI-based approach to launching.
Poco::URI validates the URI.  Added quotes to 
open sequence on OSX and LINUX.
Added optional query encoder.
Normally, most parts of the URI are encoded.
Poco::URI does not encode the query by default.
New var "uriEncodeQuery" gives option.
It is false by default to preserve backward 
compatibility for those that are pre-encoding.
Removed debug code.
Merge branch 'develop' of git://github.com/openframeworks/openFrameworks into bugfix-ofLaunchBrowser
Merge pull request #1935 from bakercp/bugfix-ofLaunchBrowser

Fixes #1934