After interruption, resume next block / trial about psychtaskframework

[shippy]

As of a3c4b65, resuming at the beginning of the interrupted block is implemented in all tasks.

[shippy]

Idea: if save-after-trial is enabled, save into Data.blocks.current, which gets deleted in every addBlock? This also enables runBlock to check which trial it should start for ((1 + height(Data.blocks.current)) : blockLen). That's similar to how block resumption goes, and maybe cleaner.

[shippy]

Crossed out a lot of unnecessary logic above. Rough sketch of the logic to be implemented:

0. Data.blocks.numRecorded is only incremented at the end of the block.
1. runBlock checks if numel(Data.blocks.recorded) is larger than Data.blocks.numRecorded.
2. If it is, then runBlock iterates k = height(Data.blocks.recorded{end}) : numTrials rather than k = 1 : numTrials.
3. appendRow runs directly on the table in Data.blocks.recorded{end}, rather than on collectedData.
4. saveData(Data) is run on every iteration of the trial if blockSettings.device.saveAfterTrial is true,
5. When all trials have run, Data.blocks.numRecorded is incremented and data is saved again if saveAfterTrial || saveAfterBlock. (The OR is important -- if saveAfterBlock were false for whatever reason, the numRecorded update could get lost.)

[shippy]

This has been put to the front of the queue at Sharon's request. Pull request #88 implements and closes this issue.