implements a simple grep feature for msfconsole

example usage:
grep https show payloads
grep -i iPhone show exploits
grep -i sp3 show targets
grep '^[\s]*generic/c' show payloads

Usage: grep [options] pattern cmd

Grep the results of a console command (similar to Linux grep command)

OPTIONS:
    -c        Only print a count of matching lines.
    -h        Help banner.
    -i        Ignore case.
    -m <opt>  Stop after arg matches.
    -v        Invert match.
adds the -A and -B options to grep

-A arg, show arg lines after match
-B arg, show arg lines before match
example:
grep -i -A 2 Reverse show advanced
added exe-only options to win32pe generation
Added XBMC Traversal exploit
Added fix URL and a few more comments. Corrected date.
warns about key size and valid time
fix typo
comply to code conventions
Add author's email
Added to create new pull request
removed | from author section
removed junk
cleaned up print_status and print_errors
Cleaned build junk
Fixed array instantiation
surrounded ntdspath in a space
Escaped quotes in windows command
Created psexec mixin to get rid of ugly copy-paste
comment in psexec.rb
Edited to fix Travis build process