Feature: Add support for eki_read program by extending iki_read, also adding --select...

Feature: Add support for eki_read program by extending iki_read, also adding --select and changing --substitute.

The eki_read is a variation of iki_read that instead supports the Extended IKI standard, known as EKI.

The iki_read and eki_read share common code.

This introduces a new parameter called `--select` or `-s`.
This allows for selecting the Vocabulary name (Object) at a given index.
I specifically chose `-s` to make the behavior more closely in line with the `-s` and `--select` from the fss_read programs.
The only difference being that the fss_read programs operate on the Content rather than the Object.

This decision forces the `--substitute` to now use `-S` instead of `-s`.
This is a breaking change that I will not back port.
The use of `--substitute` will still work with the 0.7 and 0.6 releases.

This completes the following progress commits:
- 21ae35744a1cfc7703fe3ac13b25ff7a71fa2d59
- dbc2fc03c4edd96611e07317a2c876f412017d2c
- 21ae35744a1cfc7703fe3ac13b25ff7a71fa2d59