Bourne shellized, tested in cygwin
gobal option for re:replace() in get_install_dir()

Adding global option to re:replace for the case when code:lib_dir() returns string with 2 or more ~.
Calls clear only if it is there

 In cygwin clear might not be available, so made it clear the screen using printf"\033c" when clear command not found.
Made to use -b option instead of -w for base64 in Apple OSX.
Merge branch 'master' of git://github.com/redpine50/lfetool
Merge pull request #26 from redpine50/master

Bourne shellized, tested in cygwin.

Also tested in Mac OS X.