Allow multiple template-target pairings to be specified on the command-line

[bbugyi200]

~~For example, running cookie -T c.mk Makefile -T gtest.mk tests/Makefile should initialize the two templates Makefile and tests/Makefile and open them both up in an editor.~~

When #16 is finished, the above example command would instead look like this:

cookie c.mk:Makefile gtest.mk:tests/Makefile

[bbugyi200]

Depends: #16