Allow use of the pulse library for highlighting inserted item.

The pulse library provides a mechanism for fading out the highlighting
on a region which looks pretty.  This patch adds a new variable
`browse-kill-ring-highlight-inserted-item-style' which selects between
the old default style (solid) and the new fade out style (pulse).

ChangeLog

	(browse-kill-ring-highlight-inserted-item-style) New variable, the
	style to use when highlighting newly inserted items.
	(browse-kill-ring-highlight-inserted) New function, highlights the
	newly inserted item in the required style, but only if
	highlighting is turned on.
	(browse-kill-ring-insert-and-highlight) Move highlighting code out
	into `browse-kill-ring-highlight-inserted'.
Use pulse as default for highlight-inserted-style.

Use the pulse style as the default for highlighting inserted items.
Improve comment on highlight-inserted-item-style.

Expands the comment to mention where the pulse library comes from.
Change to a summary style ChangeLog message.

Switch to a summary style ChangLog message rather than a GNU style
ChangeLog.
Merge branch 'pulse' of github.com:T-J-Teru/browse-kill-ring into T-J-Teru-pulse
Merge branch 'T-J-Teru-pulse'