reorganize Readme

Moved paragraphs around so least technical (most user-oriented) is on top, then tech/contributing (hacker info) is near the end.  This allowed to streamline the prose, but I tried to avoid changing the text as much as possible.

Linked blog in welcome section (great for finding features; helps users decide if Brackets is for them).

Used H4 vs **bold** for sub-headers.
more terse, less repeated text

(note to self; don't Push with only 4 hours of sleep)
more terse, less repeated text, ordered helping steps
Moved live highlight
From file menu to view menu.
updated pt-br translation for a better readability.
reorganize getting help
Use Python syntax highlighting for .wsgi file extensions, ie. Python web apps using mod_wsgi.
Merge remote-tracking branch 'upstream/master' into livehighlight
Changed the name to live preview highlight
Moved live preview highlight
Sort issues fixed on the Working Set and Project Tree
Switch JSLint to a submodule
Added transition to Quick View Extension.
Revert unneeded changes to jsTreeTheme
Using variables for warning colors.
Merge branch 'master' of https://github.com/adobe/brackets into larz/issue-4392
Remove default extension from untitled documents and new files
Change git to https
Fixed Quick View animation:
* Simplified positioning calculations so we don't need to keep constants in sync between the CSS and the positioning code
* Changed from using `offset()` to `css()` to set left and top (`offset()` wasn't working with the non-default transform point)
* Made the animation slightly faster (and tweaked inline editors to match)
* Made the animation grow from the top when the bubble pointer is attached at the top
Merge with Master and fix Conflict Issue