Fixing Multiple Issues

* issue#457: Page show blank if do export function without log info exist

* issue#458: The indicator is not removed upon completion when do export function

* issue#459: Background color looks ugly for availability column. Table not aligned well.

* issue#460: Filter result for template none incorrect

* update changelog for version 1.5.1

Bumping release

Preparing for release

Preparing release

Making new release.

Correcting two additional bugs then re-release

Setting up 1.3.2 release

Correctly update license for thold

Prep for release 1.3.0

Attempt to resolve issue Cacti#241

Null values in lastread column