CCLabelBMFont contentSize fix

Applied the same fix as the one applied to develop-v2 which causes the contentSize to be correctly calculated for a CCLabelBMFont instance and stops the right hand edge of the font rendering outside the right hand bounds of CCLabelBMFont.

Added a new test in LabelTest called LabelBMFontBounds

Added a new BMFont to be used in that test and LabelGlyphDesigner as the current font was missing the space character and from an old version of Glyph Designer.