Add "Container Directory" as possible pattern

- Adding a pattern like '~/some/path/{}' a project with path
'~/some/path/mycoolproject' if not other pattern match would couse the local
directory to be set to '~/some/path/mycoolproject/'

- g:rooter_merge_default_patters == 1 would not couse the definition of
g:rooter_patterns to override the default patterns