Fix bug affecting querystring keys starting with w or h

Fix bug causing any parameters starting with w or h to be removed or corrupted. Contributed by @Jeavon Also fixes #50

Improves functionality on IE 6/7/8

Handle resize event on IE 7/8, and increase image size.
Fixes “failed to ratched” errors. Improve fluidity of enforceCss when max-width no longer needs to be applied.

Many bug-fixes, better API, easier to extend.

• Only fire window.slimmage.readyCallback on first checkResponsiveImages() and when there have been actual modifications to images.
• Add window.slimmage.webpTimeout to increase likelyhood of webp usage working. Disable verbose output by default.
• Apply maxWidth after widthStep instead of before (lowers upper bound from 2080 to 2048).
• Stop inverting jpeg and webp quality values.
• Fix IE6/7 setAttribute bug; class value was not copied from noscript element.
• Add window.slimmage.enforceCSS setting; can emulate max-width on IE6/7/8, which lack an implementation.

Fix severe bug in 0.2.4 and 0.2.5

This bug is a typo that can cause images to fail to load on IE6-10.

Improves extensibility; 1 internal function name change

[deprecated - use 0.4.1 - images can fail to load]

• Make 'data.element' available to slimmage.adjustImageParameters, so plugins have more information.
• Add window.slimmage.beforeAdjustSrc callback function - this allows users to inject behavior between noscript parsing and img.src edits. (say, to offer alternate criteria, like a css class, for involving images).
• Replace adjustImageSrcWithWidth with getImageInfo, make adjustImageSrc responsible for more. Simplifies certain kinds of extension, such as background image support, as the size calculation can be reused.

Fix css size calculation when parent is floated (Safari only)

Merge #30 from Jeavon - Fix css size calculation when the parent div is floated in Safari (both OS X and iOS). (otherwise 0x0)

0.2.4 - Several bug fixes and automated tests

• Added automated test suite. Sorry for the delay in PR acceptance, but a test suite seemed essential for long-term stability.
• Merge #25 from perosb - Pass image url into data structure to allow logic based on file name.
• Merge #27 from dancek - Configurable max-width and quality parameters
• Merge #36 from dancek - Fix behavior when max-width is not defined (IE8) (replaces #18, fixes #29)
• Refactored access notations to eliminate both minification errors and lint.
• Fix bug: Perfect multiples of stepWidth were being rounded up to the next interval (images larger than needed in some instances).