Bug 1297166

Description of problem:
Some dummy commands such as /usr/bin/alias were added in #820192, but some other commands seem still missing. The POSIX standard requires "hash", "type", and "ulimit" to be available as external commands. They should be provided as dummy commands in the same way as /usr/bin/alias.

Version-Release number of selected component (if applicable):
bash-4.3.42-1.fc23.x86_64

How reproducible:
Always

Steps to Reproduce:
$ sh -c 'exec hash'
$ sh -c 'exec type'
$ sh -c 'exec ulimit'

Actual results:
$ sh -c 'exec hash'
sh: line 0: exec: hash: not found
$ sh -c 'exec type'
sh: line 0: exec: type: not found
$ sh -c 'exec ulimit'
sh: line 0: exec: ulimit: not found

Expected results:
The results should be the same as running the following command:
$ sh -c 'hash'
$ sh -c 'type'
$ sh -c 'ulimit'

Additional info:
The POSIX standard basically requires all commands that are defined in the standard to be available as external commands. The exceptions are a few commands that are categorized as "special built-in utilities", which are only required as shell built-in commands.
The standard is available at:
http://pubs.opengroup.org/onlinepubs/9699919799/utilities/toc.html