Allow -P to be invoked multiple times

If --parameters is specified more than once it is assumed
that each one contains only one parameter key=value.

This means semicolons are ignored if there is more than one -P
specified.

This should be fully backwared compatible, a single -P will
be assumed to be semicolon delimited.

Change-Id: Ic202ff3e0596b786cd5b07c53509f97a95d41585
Closes-Bug: #1224825
Closes-Bug: #1229030
Merge "Allow -P to be invoked multiple times"