Remove line in pp

[Thomasb81]

Partial PR of change done in #191

Remove new line added by preprocessor. as discuss in #166 (comment)

Note: New test test_from_subdirectory2 is a copy of existing test_from_subdirectory with subtle difference in included files:

$xxd tests/sv_pp/src/include_many_dir/dir0-a/dir1-a/file2-a.txt 
00000000: 2266 696c 6532 2d61 2e74 7874 22         "file2-a.txt"

xxd tests/sv_pp/src/include_many_dir/dir0-a/dir1-a/file2-b.txt 
00000000: 2266 696c 6532 2d61 2e74 7874 220a       "file2-a.txt".

(Ending character of file2-b.txt is LF, not easily visible in text diff)

May be the tool should test if included file end by LF to add or not the removed new-line, but adding a character not present in source code, seems not to be a good idea...