Api load path context

added a global property called load_path  that is being passed as a global to any executed file to help get a better context to load referenced scripts via a fixed path

### example:

**API**
```
api start /path/to/executing/file.py /path/to/executing
```

**file.py**
```python
# example
open(local_path + '/subfolder/supporting_file.txt')
```

---
### bug fix

Also, fixed a bug in the API  e92aa89 where it was trying to kill / remove a process that was already killed resulting in a KeyError for an out of bounds index in self.threads array which holds the alive threads array