Basic fixes

[gh0stwizard]

Hello,

This is my first pull request on github, so, probably I'm doing it wrong.
I've fixed next issues:

• added "use warnings" to all files
• updated MANIFEST file (it's missing Kex/DH.pm, Kex/DH14.pm files which cause that they will not be installed, at least on my configuration)
• using HOMEPATH environment variable to pass tests on Win32 due the missing getpwuid call on that platform, see "perldoc perlport" for details)

Thanks!