support escape char

[CJBigsharp]

slice_common.go:
const escape_char = '\'
func searchPart(value string, stop rune) (bool, string) {
var result string
escape := false
for _, char := range value {
if escape {
result += string(char)
escape = false
} else if char == escape_char {
escape = true
} else if char != stop {
result += string(char)
} else {
return true, result
}
}
return false, result
}