Do not strip BOM when linting code from the CLI

[jugglinmike]

The CLI currently strips the byte-order mark from input files, a behavior which is not shared by the Node.js API. This inconsistency led to a fair amount of confusion about JSHint's treatment of BOM characters. Update the CLI to keep the BOM intact. This behavior is more consistent, and users who understand the risk and wish to ignore it may do so by disabling warning W100.

If anyone knows a compelling case to automatically strip the BOM (since none was provided when the behavior was first introduced), please share it here