Manual Custom Modes, FEATURE_DIALOG_OPTION from Greg, simpler script, and prepare.Lion.sh fixes

Created originally on Bitbucket by 600dplus (scrax)

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Some little addition i needed for ML, I've adde minimal file list for scripts, i think it should be the only one as we can integrate HDR and FST scripts in post editing software. Added EXFAT support to make_bootable.sh and 600D consts missing for CURRENT_DIALOG_MAYBE moved shortcut button to TRASH since it's more intuitive and Q was not working for all of them. added to 500D ISO menu & flash setting from Greg codes and also other menu options like wb and drive mode and picstyle override