Abnormal number of db_query calls; caching is needed

custom_breadcrumbs_load_breadcrumbs() and custom_breadcrumbs_set_menu_breadcrumb() functions generate huge amount of identical databse queries.

Devel module shows me next queries when I load my site taxonomy/term/5 page:

duration  count  function                                 query
--------------------------------------------------------------------------------------
.......
0.09        9    custom_breadcrumbs_set_menu_breadcrumb   SELECT mlid FROM menu_links WHERE link_path = 'taxonomy/term/5'0.1278custom_breadcrumbs_load_breadcrumbsSELECT * FROM realty_custom_breadcrumbs_paths WHERE specific_path = 'taxonomy/term/5' AND language IN ('ru','') ORDER BY language ASC
0.14       78    custom_breadcrumbs_load_breadcrumbs      SELECT * FROM custom_breadcrumbs_paths WHERE specific_path = 'taxonomy/term/5' AND language IN ('ru','') ORDER BY language ASC
0.13       78    custom_breadcrumbs_load_breadcrumbs      SELECT * FROM custom_breadcrumbs_paths WHERE specific_path = 'taxonomy/term/5' AND language IN ('ru','') ORDER BY language ASC
0.21        9    custom_breadcrumbs_set_menu_breadcrumb   SELECT mlid FROM menu_links WHERE link_path = 'taxonomy/term/5'
0.11       78    custom_breadcrumbs_load_breadcrumbs      SELECT * FROM custom_breadcrumbs_paths WHERE specific_path = 'taxonomy/term/5' AND language IN ('ru','') ORDER BY language ASC
0.09        9    custom_breadcrumbs_set_menu_breadcrumb   SELECT mlid FROM menu_links WHERE link_path = 'taxonomy/term/5'
0.11       78    custom_breadcrumbs_load_breadcrumbs      SELECT * FROM custom_breadcrumbs_paths WHERE specific_path = 'taxonomy/term/5' AND language IN ('ru','') ORDER BY language ASC
.......

This is only small excerpt from log. There are much more identical queries generated by custom_breadcrumbs_load_breadcrumbs() and custom_breadcrumbs_set_menu_breadcrumb() functions to load the page.
I believe it is very expensive to make hundreds database queries in order to show just breadcrumbs.

Suggested patch makes use of static variables to cache identical queries in mentioned functions.