This reverts commit 3e24194c.

the check is redundant in the context of the fetch_by_location calling
method, since it already performs the same check.

Extending support so locations like X:g.1-10 are parsed as a genomic
coordinate. Also added some comments as the regular expressions are
slightly cryptic.

Allow a seq_region_name of 0 to be returned from Slice, and do a little test to ensure we can create a Slice with name 0.

- Corresponding test to test functionality

Use "INSERT INTO table (col1, col2) VALUES (val1, val2) instead.

[Adaptors]

when removing slice, remove any attached assembly entries

works similar to store_assembly, used to check if assembly entry already exists between 2 slices before attempting to store
also corrected typo in store_assembly method, table used is assembly, not analysis

Other schemas may need this which do not go through a process of removing
old/retired seq region ids in favour of their new ids. When querying by a slice
this is automatically delt with. When fetching by an ID you now need to
force the search on.