Split boot.js in two to allow the env to be configured in between

This is mainly intended to support jasmine-browser-runner, which will load
a script that configures the env in between the two boot files (boot0.js and
boot1.js). The single-file boot.js is retained for now but will be removed
in a future release.

lib/jasmine-core.rb

@@ -6,7 +6,7 @@ module Jasmine
       end
 
       def js_files
-        (["jasmine.js"] + Dir.glob(File.join(path, "*.js"))).map { |f| File.basename(f) }.uniq - boot_files - node_boot_files
+        (["jasmine.js"] + Dir.glob(File.join(path, "*.js"))).map { |f| File.basename(f) }.uniq - boot_files - ["boot0.js", "boot1.js"] - node_boot_files
       end
 
       SPEC_TYPES = ["core", "html", "node"]