Added outbox folder, random .png containers

Added:
* /outbox/ folder for created by user nanoposts
* Added /containers/ folder for blank .png container storage and random
selection of container from it

Fixed:
* In posts tree view, if post doesn't have attach, image wont show at
all
* In posts tree view, auto adjusting size of text area if there is no
attach image
* In posts tree view, wheel scrolling is now smooth

Version bump to 1.1a