Bug #56681 MEB renaming is incomplete, link to innobackup is missing

Description:
BUG#56610 (Replace the toolname "innobackup" with "mysqlbackup") has not been completely fixed.

A build of the new mysqlbackup does not remove an existing innobackup in the build directory. "make clean" does not remove it either.

Also I'm missing a link (symbolic or hard or copy, depending on platform capabilities) from mysqlbackup to innobackup.

How to repeat:
Have a build of innobackup around, or retrieve one by branching meb-3.5.next up to revno 227 and build it.

Pull from meb-3.5.next (revno 228).
Build.

See that innobackup is still there, but not a s alink to the new mysqlbackup.
Run "make clean".
See that mysqlbackup has gone, but innobackup is still there.

Suggested fix:
The build of mysqlbackup should include the removal of innobackup and linking mysqlbackup to innobackup.

The make target "clean" should include a removal of innobackup.

Committed a new patch for review.
Following changes have been incorporated:
- The fix creates the symbolic link in the build directory.
- The use of out-of-source build is highly recommended for use with cmake.
  The README file is updated to add a note for this.
  The default "clean" target may not clean everything while using in-source
  build. This is acceptable limitation provided one uses out-of-source build.
- "make install" copies over mysqlbackup executable and innobackup 
  link/executable over to ${CMAKE_INSTALL_PREFIX} directory. This works well 
  on all unix platforms and may not be applicable with other non-makefile 
  based build systems. cmake -P cmake_install.cmake *may* work on some
  platforms where "make install" is not applicable. The README file has been
  updated accordingly.

Not approved. Please see email for small change requests.

Patch of 2010-09-20. All looks fine. No comments.