Read JDWP options from runtime

Allocates JDWP::JdwpOptions on the heap and copies parsed options to
avoid the need to include jdwp/jdwp.h into runtime.h file.

Also does some minor cleanup and removes the old JDWP options parsing
code that became dead code after we move it to the new command-line
parser.

Bug: 19275792
Change-Id: I71901c89fbf2cc3c1901a089e2a98b4326c6ee70