[FlxBitmapFont] allow extra whitespace when parsing bmfont rows

[MondayHopscotch]

Some exporters can align the columns so that the file is easier to view as a human:

char id=  32 x=    1 y=    1 width=    8 height=    8 xoffset=    0 yoffset=    0 xadvance=    8 page=0 chnl=15
char id=  33 x=   10 y=    1 width=    5 height=    8 xoffset=    0 yoffset=    0 xadvance=    5 page=0 chnl=15
char id= 101 x=   46 y=   37 width=    8 height=    8 xoffset=    0 yoffset=    0 xadvance=    8 page=0 chnl=15

The previous parsing did not allow for spaces after the =, such as this example:

char id=98 x=19 y=37 width=8 height=8 xoffset=0 yoffset=0 xadvance=8 page=0 chnl=15
char id=99 x=28 y=37 width=8 height=8 xoffset=0 yoffset=0 xadvance=8 page=0 chnl=15
char id=100 x=37 y=37 width=8 height=8 xoffset=0 yoffset=0 xadvance=8 page=0 chnl=15

[Geokureli]

created testTextFormatWithSpaces, so that when something fails we know exactly what failed