Added background image version 1.1 for MacOSX dmg folder

Changed graphics for new version 1.1. Now only non-negative values are admitted.

Fixed bug: now there is no limit to the size of the coefficient matrix of the linear problem

Modified scalc.pro and .gitignore files

Improved ctrl+c and ctrl+v support. Reviewed icons and paths. Modified the about dialog

Added shortcuts ctrl+c and ctrl+v

Added application icon image for Mac OS X

Modified main window title

Merge branch 'master' of https://bitbucket.org/debussy/scalc

Modified application icon

Modified .gitignore

First commit