prepare for v1.7

Prepare 1.6.2 release

Prepare 1.6.1 release

Clean autotools, fixes: make dist

Bump version to 1.5.4 and update ChangeLog

Remove a unneded #include header in the public hunspell.hxx

Update changelog for v1.5.2

Add header to makefile.am

Backport a fix for iterator decrement past begin

Past begin() iterator decrement error

VS Debug build threw error on decrement past begin.

(cherry picked from commit cb1535b)