App controller for sortmerna mapper

+ doc strings edited.
Can you describe what the regular expression is supposed to do?  Perhaps it would be fastest to provide a few examples of the types of lines that will satisfy the ```elif``` on line 300.

The reason I'm asking is that I'm not sure this is grabbing exactly what you want:
```python
>>> import re
>>> line = 'Total reads for de novo clustering = hello'
>>> line2 = 'Total reads for de novo clustering = (hello'
>>> re.split('Total reads for de novo clustering = | \(', line)[1] # this looks correct
'hello'
>>> re.split('Total reads for de novo clustering = | \(', line2)[1] # this doesn't
'(hello'
>>>
```
But I'm not sure if I'm interpreting the intention correctly.