Bug 2629: add char-with-stroke support to word-phrase-utf.chr

Bug 2629: add char-with-stroke support to word-phrase-utf.chr

This patch adds diacritic search support for the following characters-with-stroke:
a,b,c,d,e,h,l,r,t,u,y,z

Handles both uppercase and lowercase mappings.

Also corrects a note in word-phrase-utf.chr:  the 'equivalent' command is NOT for searching,
but rather for sorting.  See Zebra manual: http://www.indexdata.com/zebra/doc/character-map-files.html,
near the bottom.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Some notes:
- Copied the file to my koha-dev folder and reindexed
- Tried some simple searches like: Süden and Suden, schon und schön with success
- Added some of the new characters to a record and tried search with and
  without diacritics (ɨƗʉⱥɆɌ and iiuaer) with success.

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>