"Context" and "Unified" renderers should handle "No EOL at EOF"

[jfcherng]

When it involves in "No EOL at EOF", the current diff output can not be successfully applied via GNU patch. The correct result can be generated by GNU diff with

# for Context with extra one line context
# " | tail -n +3" removes those 2 file path headers
$ diff --context=1 old_file.txt new_file.txt | tail -n +3

# for Unified with extra one line context
# " | tail -n +3" removes those 2 file path headers
$ diff --unified=1 old_file.txt new_file.txt | tail -n +3

old_file.txt (no EOL at EOF):

A
B
X

new_file.txt (has EOL at EOF):

A
C
X

---

Our current outputs (Context):

***************
*** 1,3 ****
  A
! B
  X
--- 1,4 ----
  A
! C
  X
+ 

GNU diff (Context):

***************
*** 1,3 ****
  A
! B
! X
\ No newline at end of file
--- 1,3 ----
  A
! C
! X

---

Our current outputs (Unified):

@@ -1,3 +1,4 @@
 A
-B
+C
 X
+

GNU diff (Unified):

@@ -1,3 +1,3 @@
 A
-B
-X
\ No newline at end of file
+C
+X

[jfcherng]

Should have been fixed in 3fdad9c.