fix CTextFile line recognition

[lifenjoiner]

This may break the logic of dependents!

• line encodings are the tail part of a line, and then can be shown

Test example with grepWin (needs patch stefankueng/grepWin#455):

1. File:
   1.1. the last line is empty

   AAAAAA
   AAAAAA
   
   BBBBBB
     AAA
   BBBBBB
   BBB
   CCC
   
   

   1.2. append something to the last line, but no new line

2. Line encoding
   2.1 \r
   2.2 \n
   2.3 \r\n
   2.4 Mixture for patches generated by git for windows.

3. Search pattern
   3.1. A+\s+B+
   3.2. C+\s+