[AESH-258] Update Aehs build instruction
Merge pull request #85 from danielsoro/master

[AESH-258] Update Aehs build instruction
changed optionvalidatorprovider, no need for it to be so "complex"
[AESH-257]
added OptionActivatorProvider, no hook for it yet
[AESH-257]
added postProcessing of commands/options so we can support optionactivators
being enhanced by the provider
[AESH-257]
added test to verify that optionactivatorprovider works as intended
a simple test to show how to run æsh in a script
a simple explanation