Reworked the parser into its own class and got it out of the Loader
Added build instruction to the README
Support for push / pop instructions
Added description for push / pop instructions
Store more contextual information in the stack so it can be balance-checked and safely used for call/ret later
Added a line to the docs about balancing pops and pushes
Added parser / execution support for sections, specifically '.entry'
'call' and 'return' instructions added.
Tidying up comment about rebasing