[RFA_v2 0/8] Implement 'frame apply COMMAND', enhance 'thread apply COMMAND'

[Philippe Waroquiers <philippe dot waroquiers at skynet dot be>]

This is the third iteration of the patch series that:
 * implements a new command
     'frame apply [all | COUNT | -COUNT] [FLAGS...] COMMAND'.
 * enhance 'thread apply COMMAND' by adding FLAGS arguments.
 * adds some shortcuts commands
 * documents the above in gdb.texinfo and NEWS.
 * adds a unit test for cli-utils.c
 * adds test for 'frame apply'
 * modify gdb.threads/pthreads.exp to test 'thread apply' -FLAGS argument

The first version was an RFC
  * Code and doc was complete, but was lacking ChangeLog and tests.
  * Comments received from Eli and Simon.

The second version was RFA v1:
  * Replied to all comments of Eli and Simon.
  * Tests and ChangeLog entries added.
  * Comments received from Pedro

This version handles the comments of Pedro about giving the flags
individually.

The changes compared to RFA v1 is:
  * The flags must be given individually, such as -v -v -c.
  * The documentation and on-line help was updated accordingly.
  * ChangeLog information is distributed in each commit log message.