Add test harness for stowrc files

Why:

* Planning on developing a new feature for parsing of stowrc files.
* Need a test harness that performs initialization and clean up
    * Initialization: Create directory structure that allows creation of
      stowrc files without worrying about squashing existing files.
    * Clean up: Remove all files created during testing.

This change addresses the need by:

* Add intialization and cleanup harness in t/rc_options.t
    * Define the location to write stowrc files to in $RC_FILE
    * Ensures that location $RC_FILE does not already exist.
    * Calls the init_test_dirs to bootstrap directory tree.
    * After all tests are run, removes $RC_FILE and the testing
      directory tree.

* Add basic test of stowrc parsing to t/rc_options.t
    * Provides a template of how to create and test a stowrc file.

* Newly created t/rc_options.t file added to MANIFEST

MANIFEST

@@ -45,6 +45,7 @@ t/ignore.t
 t/join_paths.t
 t/parent.t
 t/stow.t
+t/rc_options.t
 t/testutil.pm
 t/unstow.t
 t/unstow_orig.t

t/rc_options.t

@@ -0,0 +1,53 @@
+#!/usr/local/bin/perl
+
+#
+# Test processing of stowrc file.
+#
+
+use strict;
+use warnings;
+
+use Test::More tests => 2;
+
+use testutil;
+
+require 'stow';
+
+# stowrc file used for testing.
+my $RC_FILE = "$OUT_DIR/.stowrc";
+# Take the safe route and cowardly refuse to continue if there's
+# already a file at $RC_FILE.
+if (-e $RC_FILE) {
+    die "RC file location $RC_FILE already exists!\n";
+}
+
+# Define the variable that will be used to write stowrc.
+my $rc_contents;
+
+# Init testing directory structure and overwrite ENV{HOME} to prevent
+# squashing existing stowrc file.
+init_test_dirs();
+
+# =========== RC Loading Tests ===========
+# Basic parsing and loading rc file tests.
+# ========================================
+
+#
+# Test stowrc file with one options per line.
+#
+local @ARGV = ('dummy');
+$rc_contents = <<HERE;
+    -d $OUT_DIR/stow
+    --target $OUT_DIR/target
+HERE
+make_file($RC_FILE, $rc_contents);
+my ($options, $pkgs_to_delete, $pkgs_to_stow) = process_options();
+is($options->{target},  "$OUT_DIR/target", "rc options different lines");
+is($options->{dir}, "$OUT_DIR/stow", "rc options different lines");
+
+#
+# Clean up files used for testing.
+#
+unlink $RC_FILE or die "Unable to clean up $RC_FILE.\n";
+remove_dir($OUT_DIR);
+