WL#963: Make table aliases case insensitive on all platforms

Affects: Server-7.1   —   Status: Assigned   —   Priority: Medium

According to Peter Gulutzan, major SQL standards and according to the behaviour of  
many major RDBMS's, table aliases should be case insensitive on all platforms.

Due to the possibility that many of our users are relying on case sensitive
table aliases, case sensitivity should be provided as a startup option, like
with --old   option.