Add multi shot

Allows multiple shots aa=gdat([81751 81745 81830],'ip','doplot',1); %with doplot=1: new figure, then -1 (hold on) also adding to the figure with -1: aa=gdat([81741],'ip','doplot',-1); aa=gdat([81811 81815],'ip','doplot',-1);

requested review from @afrank

assigned to @amerle

added 3 commits

• acbc3829...fe7d7d16 - 2 commits from branch master
• 96add5db - Merge branch 'master' into add_multi_shot

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added 1 commit

• 955eb64b - simplify if statement

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resolved all threads

I didn't spot anything in the code. I tested a bit with different shots/requests and works well!

merged