Fix -data-read-memory-bytes command (MI)

Summary:
* Add IsHexadecimalNumber method to CMIUtilString (MI)
* Add number format (dec,hex,auto) to CMICmdArgValNumber (MI)
* Fix -data-read-memory-bytes to pass address in hex format (MI)
* Fix output begin/end/offset fields format in -data-read-memory-bytes
* Fix CMICmdArgValNumber::ExtractNumber to extract 64bit value
* + tests

All tests passed on OS X

Reviewers: abidh, zturner, clayborg

Reviewed By: clayborg

Subscribers: lldb-commits, zturner, clayborg, abidh

Differential Revision: http://reviews.llvm.org/D7610

llvm-svn: 229132