Update status bar selection texts

[ProgerXP]

After #204 it became confusing which of the two numbers is line, which is byte count. Currently the format is "Sel %d : %d". Make it so: Sel %d L : %d B (remember we have several status bar format strings, all relevant should be changed).

[cshnik]

Done.

[ProgerXP]

Add L to rectangular selection's status text.

[cshnik]

Done.