fix block help text

Part of the patches for the whole block visibility by role issue included a bunch of improvements to the help text for block.module. the old patch doesn't apply anymore, and at drumm's suggestion, i just manually rolled a new patch that only deals with the help text. the version of functionality described here is still current with the 4.7.0 version of block, so this patch could be applied against DRUPAL-4-7, in addition to HEAD. of course, the Block handbook page will need updating once patch is applied, too.

Here's the help text provided by this patch (most of the links here are broken, i just cut and pasted from "view source" out of my local test site...):

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Blocks are boxes of content that may be rendered into certain regions of your web pages, for example, into sidebars. Blocks are usually generated automatically by modules (e.g., Recent Forum Topics), but administrators can also define custom blocks.

The region each block appears in depends on both which theme you are using (some themes allow greater control over block placement than others), and on the settings in the block administration section.

The block administration screen lets you specify the vertical placement of the blocks within a region. You do this by assigning a weight to each block. Lighter blocks (those having a smaller weight) "float up" towards the top of the region; heavier ones "sink".

A block's visibility depends on:

• Its enabled checkbox. Disabled blocks are never shown.
• Its throttle checkbox. Throttled blocks are hidden during high server loads.
• Its page visibility settings. Blocks can be configured to be visible/hidden on certain pages.
• Its custom visibility settings. Blocks can be configured to be visible only when specific conditions are true.
• Its user visibility settings. Administrators can choose to let users decide whether to show/hide certain blocks.
• Its function. Some dynamic blocks, such as those generated by modules, will be displayed only on certain pages.

Module blocks

Some modules generate blocks that become available when the modules are enabled. These blocks can be administered via the blocks administration page.

Administrator defined blocks

Administrators can also define custom blocks. These blocks consist of a title, a description, and a body which can be as long as you wish. Block content can be in any of the input formats supported for other content.

You can

• enable, throttle and configure blocks at administer >> blocks.
• add an administrator-defined block at administer >> blocks >> add block.

For more information please read the configuration and customization handbook Block page.