Script tests re-added, all tests can run under gdb

Also fixed a minor bug with printing, and removed the ability to
configure the parser.

Added and updated QUICKSTART.md as a quick way to get people started.

There's some broken scripts under 'scripts/' that require functions to
work properly.

tests/scripts/test_keyword_print.toy

@@ -0,0 +1,21 @@
+//basic print statement
+print 42;
+
+//print compount expressions
+print 3 * 5;
+
+//print a string
+print "Hello world!";
+
+//print a concatenated string
+print "Hello" .. "world!";
+
+//print with escaped characters
+print "\tHello\nworld!";
+
+//print from a substring string
+print "Hello world"[0,5];
+
+//print from a substring, after a concat
+print ("hello" .. "world")[2,6];
+