Validate options of Codenvy bootstrap script

[vkuznyetsov]

Validate options which user passes to Codenvy bootstrap script.
If option is unknown, display warning at start like the follow:
{noformat}
[CODENVY] Welcome. This program installs Codenvy 3.14.2-SNAPSHOT.
[CODENVY] !!! You passed a parameter named no-proxy. This is an unrecognized parameter.
[CODENVY] !!! You passed a parameter named http-proxy. This is an unrecognized parameter.
[CODENVY] !!! You passed a parameter named https-proxy. This is an unrecognized parameter.
[CODENVY] Proceed? [y/N]
{noformat}

[dmytro-ndp]

I propose to change output slightly to handle parameters with value, flags and typos:

[vagrant@dev ~]$ ./install-codenvy.sh --http-proxy=http://test --unknown typo