Record and summarise resource usage from a quantification run.
Write file containing accumulated per-run resource usage.

Only for quantification commands at the moment (i.e. not prequantification
yet). n.b. code untested yet.
Merge branch 'develop' into issue50
Plot time and memory usage for quantification step.

Not tested yet.
Add placeholder func for plotting prequant usage.
Make collection of resource usage stats optional.

e.g. for case where /usr/bin/time is not available.
Fix broken test.

Not sure why pre-commit git hook is not being run on this branch?
Additional work to make resource usage stats optional.
Prequantification may also involve multiple commands.

In which case we need to calculate resource usage summaries across them too.
Tweaks to resouce usage statistic filenames.

n.b. This is all still entirely untested.
Start documenting collection of resource usage statistics.
Documentation typos.
A couple of fixes to get usage code to run.
Stray period typo crept into timed pipes.
Some values in options file were still being overwritten by defaults.

Added a couple of tests to check for this.
Bug fixes, tidy resource_usage.py, and spruce up plots.
Max memory recorded in Gb, times in seconds log base 10.
Reduce code duplication in multi-quant run plots.

Although better than before (the monster functions have been split up), the
code for drawing plots over multiple quantification runs in plot.py is still
pretty hard to understand. Needs commenting well at the least.
Protect command with quotes in usage CSV files.
Fix resource usage graphs directory name.

Must get a new keyboard with a functional "c" key.