Be more liberal in accepting filenames
Be more liberal in accepting filenames

The convention '.tmp' for templates and '.yaml' is useful. However,
many people have filename completion in their shell, so it can happen
that when tab-ing, the full filename appears (e.g. 'enum.yaml').

Allow user to specify with or without suffix, without breaking the
previous convention established by this program.

For example, both the following now work:
 > easygen -tf enum_go target_mirror_type.yaml
 > easygen -tf enum_go.tmpl target_mirror_type

go-easygen/easygen,suntong001/easygen,suntong001/easygen,suntong/easygen,suntong/easygen,go-easygen/easygen,go-easygen/easygen,suntong/easygen,suntong001/easygen