Fixes to makefile.pl to ensure easy install of dependencies with cpanminus. wording update in readme

Makefile.PL

@@ -2,13 +2,11 @@ use ExtUtils::MakeMaker;
 
 WriteMakefile(
     NAME          => 'pshell',
-    VERSION_FROM  => 'lib/History/SQLite.pm',
     PREREQ_PM     => {
         'DBI'               => 0,
         'DBD::SQLite'       => 0,
         'Term::ReadLine'    => 0,
         'Cwd'               => 0,
         'File::HomeDir'     => 0,
-        'Environment::SQLite' => 0,
     },
 );