Issue #130: Fixed support for indenting by tab
Allow indent a block of code by selecting a range of lines
and pressing 'tab'. The behavior implemented is the same as
the one in Sublime Text editor since I found it intuitive enough.
#define off_width 32
#define off_height 32
static unsigned char off_bits[] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0xbc, 0xc9, 0x34, 0x3d, 0x84, 0x29, 0x35, 0x05, 0x84, 0x2a, 0x54, 0x05,
0x9c, 0x2a, 0x54, 0x1d, 0x84, 0xac, 0x95, 0x05, 0x84, 0x2c, 0x95, 0x05,
0x84, 0x28, 0x15, 0x05, 0xbc, 0xc8, 0x14, 0x3d, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0xe7, 0x3d, 0x00, 0x80, 0x28, 0x04, 0x00,
0x80, 0x28, 0x04, 0x00, 0x80, 0xe8, 0x1c, 0x00, 0x80, 0x28, 0x04, 0x00,
0x80, 0x28, 0x04, 0x00, 0x80, 0x28, 0x04, 0x00, 0x00, 0x27, 0x04, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};