Add DiffIgnoreWitespaceEol and deprecate DiffIgnoreWitespaceEol (#774)

DiffIgnoreWitespaceEol contains a typo and does not have the same name as it's libgit2 counterpart.

Fixes #773

Author: zegl

deprecated.go

@@ -72,6 +72,13 @@ func NewCredDefault() (*Cred, error) {
 	return NewCredentialDefault()
 }
 
+// diff.go
+
+const (
+	// Deprecated: DiffIgnoreWhitespaceEol is a deprecated alias of DiffIgnoreWhitespaceEOL.
+	DiffIgnoreWitespaceEol = DiffIgnoreWhitespaceEOL
+)
+
 // features.go
 
 const (

diff.go

@@ -487,7 +487,7 @@ const (
 
 	DiffIgnoreWhitespace       DiffOptionsFlag = C.GIT_DIFF_IGNORE_WHITESPACE
 	DiffIgnoreWhitespaceChange DiffOptionsFlag = C.GIT_DIFF_IGNORE_WHITESPACE_CHANGE
-	DiffIgnoreWitespaceEol     DiffOptionsFlag = C.GIT_DIFF_IGNORE_WHITESPACE_EOL
+	DiffIgnoreWhitespaceEOL    DiffOptionsFlag = C.GIT_DIFF_IGNORE_WHITESPACE_EOL
 
 	DiffShowUntrackedContent DiffOptionsFlag = C.GIT_DIFF_SHOW_UNTRACKED_CONTENT
 	DiffShowUnmodified       DiffOptionsFlag = C.GIT_DIFF_SHOW_UNMODIFIED