Update assocation logic to allow multiple dots and longer extensions

[dwgras]

Allow for more than 1 extension and more than 3 characters in extensions

[Gregg Young]

The limitation is in filldir.c IDFile(). The code is pretty primitive. It supports only 3 character extensions for a fixed number of file types and there is not way to make this more flexible without a complete rewrite.

[Gregg Young]

New flag for associations related to length from final period.

0 - no period strnchar \ to cut filename then strnchar . = null 1 - period followed by nothing or wild card cut filename token on . use final token strlen = 1 2 - period followed by 1 char same as 1 but strlens = 2 3-100 same as above (no number limit imposed)

string compare (no case) to association filemask 0s & 1s would be comp to masks of style "xxx" "xxx." "xxx.*" after dropping the '.' & '*' from all strings.

Need to handle xxx* mask strcpy filename to string of strlen = mask - 1 run against all filenames

string compare for .xxx final token from above (extension of any length) would drop use strlens then compare to the appropriate flag numbered filemasks *xxx would be handled by replacing the '*' with a '.'

Assumptions

1. Final extension is the file type indicator as opposed to first extention
2. Associations by filename should be allowed including allowing wild card extensions
3. Compare would be done directly on any filenames without wildcards
4. Wildcards only at beginning and end. Could handle ones in the middle but do we need to?
5. Arbitrarily long extensions permitted
6. Exact matchs