Make methods in SystemExtensions public

Most of the methods rely on instance variables, so it does not
make sense that they should be available as module methods.
But when they are included into the HighLine class, they
are private, so no useful outside of the class.

Making the methods public doesn't seem to have a negative
effect on test results, and it allows the methods to be called
on instances of the HighLine class.
Merge pull request #70 from presidentbeef/make_system_extensions_methods_public

Make methods in SystemExtensions public
remove deprecate warning on Windows

HighLine is using the Win32API, but Win32API is obsolete.
(Win32API = DL Wrapper)
And, DL is deprecated after Ruby 2.0.0.

case 1: use Ruby 2.0.0 : `DL is deprecated, please use Fiddle`
case 2: use Ruby 1.9.3 : `Win32API is deprecated after Ruby 1.9.1; use dl directly instead`
Merge pull request #71 from whiteleaf7/master

Remove deprecate warning on Windows
Adding support for non US-ASCII encoded menu items

- Eval the menu template in the interpreter's default_external encoding,
  which will probably be utf8, or something like windows-1252 on win32
- Added test with utf8 char in it
Merge pull request #73 from dalyons/master

Adding support for non US-ASCII encoded menu items
fix problem #75
Merge pull request #76 from whiteleaf7/master

fix problem #75
Preparing for release.
fix undefined method terminal_size. It adds extend self on system extensions module
Merge pull request #79 from rubemz/bugfix/terminal-size

fix undefined method terminal_size.
Preparing for release.
Add test for terminal_size
Fix terminal_size for JRuby >= 1.7.0

to call get_width and get_height instead of
getTerminalWidth and getTerminalHeight
Merge pull request #80 from presidentbeef/terminal_size_jline

Fix terminal_size to work with jline2
Updating the CHANGELOG.
Version bump.
dup statement in `#say`
Add test for frozen statement
Merge pull request #82 from davispuh/patch-3

dup statement in `#say`