This PR borrows code from https://golang.org/x/lint to automatically fix initialisms and stuttering in generated names. Thanks to @Green7 for the initial implementation in #22! This PR resurrects #32, which was closed automatically when a child branch was merged.

Docs for this change:

• Initialisms: names with ID or URL or other well-known initialisms will have their case preserved. For example Id would lint to ID, and ApiBaseUrl would lint to APIBaseURL.
• Stuttering: it will attempt to remove repeated prefixed names from enum values. An enum value of type Foo named Foo_FOO_BAR would lint to FooBar.

To lint all generated Go names, add option (go.lint).all = true to your proto file. To lint only enum values, add option (go.lint).values = true. To specify one or more custom initialisms, specify an initialism with option (go.lint).initialisms = 'HSV' for the HSV initialism. All names with HSV will preserve its case.

option (go.lint).all = true;
option (go.lint).initialisms = 'RGB';
option (go.lint).initialisms = 'RGBA';
option (go.lint).initialisms = 'HSV';

enum Color {
	// PROTOCOL_INVALID value should lint to ProtocolInvalid.
	PROTOCOL_INVALID = 0;
	// PROTOCOL_IP value should lint to ProtocolIP.
	PROTOCOL_IP = 1;
	// PROTOCOL_UDP value should lint to ProtocolUDP.
	PROTOCOL_UDP = 2;
	// PROTOCOL_TCP value should lint to ProtocolTCP.
	PROTOCOL_TCP = 3;
}

message Color {
	oneof value {
		// rgb should lint to RGB.
		string rgb = 1;
		// rgba should lint to RGBA.
		string rgba = 2;
		// hsv should lint to HSV.
		string hsv = 3;
	}
}