database.*.inc: coding style cleanup + minor internal enhancement

some more minor update to:

1. database.mysql-common.inc => _db_create_field_sql(): change SQL words case
2. all => db_escape_string(): sync input variable name with db_decode_blob()

no logical change but only code clean up and sync style

patch updated via latest CVS HEAD, plus minor update to db_query_temporary() and db_query_range(). i change this 2 function as a simple query rewriter, and pass result to db_query() directly for execution (but not _db_query()). e.g. in case of mysql/mysqli:

function db_query_range($query) {
  $args = func_get_args();
  $count = array_pop($args);
  $from = array_pop($args);
  array_shift($args);

  $query .= ' LIMIT '. (int) $from .', '. (int) $count;
  if (isset($args[0]) and is_array($args[0])) { // 'All arguments in one array' syntax
    $args = $args[0];
  }
  return db_query($query, $args);
}

it seems may have performance degrade (as one more layer of function call), but a benchmarking show out a positive result (reuse all setup as http://drupal.org/node/172541#comment-298711):

                  +-------------+---------------+----------------+
                  | c1, n500    | c5, n500      | c10, n500      |
+-----------------+-------------+---------------+----------------+
| D6 HEAD         | 289 +- 11.5 | 1429 +- 342.4 | 2888 +- 721.0  |
+                 +-------------+---------------+----------------+
|                 | 294 +- 16.1 | 1436 +- 162.3 | 2955 +- 2123.6 |
+                 +-------------+---------------+----------------+
|                 | 294 +- 15.7 | 1424 +- 413.6 | 2826 +- 774.5  |
+-----------------+-------------+---------------+----------------+
| D6 HEAD + patch | 290 +- 13.8 | 1450 +- 402.0 | 2815 +- 770.2  |
+                 +-------------+---------------+----------------+
|                 | 290 +- 12.6 | 1416 +- 215.8 | 2855 +- 666.5  |
+                 +-------------+---------------+----------------+
|                 | 290 +- 17.0 | 1464 +- 441.9 | 2912 +- 884.8  |
+-----------------+-------------+---------------+----------------+

this change should able to decrease the workload of database driver maintenance, without losing any performance. hope someone may help about its commit :)

patch still apply to CVS HEAD.

patch still apply to CVS HEAD. rename issue title.

patch updated via CVS HEAD. seems this should be a minor bug report but not feature request :)

I guess this is a bug fix, since it improve usability of code, decrease the difficulty of maintenance and standardize the coding standard for developers. This is not a "hard" bug but "soft".

It is not functionality fix, as we will not died without this patch, so it is minor.

We are able to cleanup these lossy coding style in D6, without affect any existing code related nor performance; it don't add/drop any API functions; it is transparency to all contribute developers. It should be suitable for D6 as an enhancement. I guess coding style cleanup is always welcome even after beta1, isn't it?

This issue will make as duplicated, as its handling is already split into numbers of small patches, for a easy review and commit. Please refer to the following issues:
http://drupal.org/node/183892 (Group up database.mysql-common.inc)
http://drupal.org/node/183896 (Tidy up database.pgsql.inc)
http://drupal.org/node/183902 (Tidy up database.inc)
http://drupal.org/node/183910 (Simplify db_query_range() and db_query_temporary())