ChangeLog: Move all ChangeLog files to .pre-gitlog

From v1.16.1 onwards, Wget no longer maintains an active ChangeLog file.
Instead the ChangeLog will be automatically generated on each release
through gnulib's gitlog-to-changelog script. However, the old versions
of the ChangeLog files are retained for reference. These files are
renamed with a .pre-gitlog appended to their filenames.
Also removed ChangeLog.README file which is not required anymore

ChangeLog.README

@@ -1,16 +0,0 @@
-Please note that Wget has more than one ChangeLog file:
-
-    ./ChangeLog: documents changes to files in the top-level directory
-                 and to files in subdirectories like po/ that don't have
-                 their own ChangeLogs
-
-    src/ChangeLog: documents only changes to files in the src directory
-
-    doc/ChangeLog: documents only changes to files in the doc directory
-
-    windows/ChangeLog: documents only changes to files in the windows directory
-
-    msdos/ChangeLog: documents only changes to files in the msdos directory
-
-When checking to see if a patch you sent in has been applied, please
-look in the appropriate ChangeLog(s).

ChangeLog.pre-gitlog

@@ -3294,4 +3294,3 @@
 
 	* aclocal.m4 (AM_WITH_NLS, AM_GNU_GETTEXT, AM_LC_MESSAGES,
 	AM_PATH_PROG_WITH_TEST): from gettext-0.10.32.
-

tests/ChangeLog.pre-gitlog

@@ -1155,4 +1155,3 @@
 	testing is supported at the moment).
 
 	* test1: Added basic HTTP test.
-