#258 evaluate browsecommand on "activate {}"

[Tobias]

From the tktable manual:
-browsecommand
"Specifies a command which will be evaluated anytime the active cell changes."

This isn't entirly true. When the command "$w activate {}" is invoked the browsecommand isn't evaluated.

I've attached a patch which fixes this bug.
When "$w activate {}" is invoked, it'll evaluate the browsecommand. However these %-sequences will be expanded like this:
%S: a null string
%c colorigin - 1
%r roworigin - 1

All other sequences are expanded as usual.
%c and %r are superfluous, but they must be set to something...

Perhaps one should add an option which activates this feature, so we won't violate POLA. Since no applications expects that %S will expand to a null string.

[Tobias]

Patch