Improve EDID cleaner for hex uploads

[pp3345]

Try harder to disambiguate addresses from actual values. For example, previously cases where all values were prefixed with 0x wouldn't work correctly.

[coveralls]

Coverage increased (+0.003%) to 99.065% when pulling 84c89fbe3e1867d04e6933fd806e81c26e9f5f8c on pp3345:better-hex-parsing into 660e40b0ec8ec8da7bdea267b959150d535dfbf5 on timvideos:master.