fixed bug with cache entries being overwritten when 'module' was registered under 'module/index'

[gustaff-weldon]

Let's assume there's a module registered under "test/index"

When you call require( "test" ) stitch checks if it has such module in cache under "test" path.
If not it checks, if there's such module defined under "test" or "test/index" and tries to load it.
In this example, It finds the module under "test/index" so it creates cache entry for that path.

When the same module is required again, it will be not found in cache and whole cache entry is recreated (module function will be invoked again)