Merge pull request #138 from kamalpreetgrewal/master

implements select window
Sets/resets the flags on entity selection
Merge pull request #140 from aseemmittal/master

Sets/resets the flags on entity selection
corrects paste position of circle and ellipse and other code correction
Merge pull request #144 from ChanKaur/chan

corrects paste position of circle and ellipse and other code correction
hide/show of status bar
Merge pull request #145 from CharuChopra84/master

hide/show of status bar
generalizes the drawing of entities
Merge pull request #147 from bhattigurjot/master

generalizes the drawing of entities
close active subwindow
Merge pull request #148 from CharuChopra84/master

close active subwindow
implements scripting through functions
adds scripting for text
adds script function for arc entity
Merge pull request #149 from bhattigurjot/master

implements scripting through functions
implements grid, zoom-in/out actions