Adds a method classifier

- adds Helios command to classify unclassified methods
strat to implement chain of responsibility
Merge remote-tracking branch 'upstream/master' into classifier
Passes done over the classifier

- Introduces a `chain of responsibility` pattern
- Renames `execute` into `classify`
- Renames `classify` into `doClassify`
Gives focus on input in `HLRequestWidget`

- Extracts the superclass behavior of giving focus to the button
- Overrides this code in `HLRequestWidget` to prevent this behavior
- Gives focus to the input
validation of --base-path only directories.
FileServer:checks --base-path but only warns on problem values
FileServer --base-path validation checks are async and console warn:
FileServer>>validateBasePath clean space stat parameter;used ifNil:ifNotNil on err; reformatted warning messages.
Rewrote AmberCli.st from IDE
Fix {Boolean,Number,String} >> =

It failed when compared with JS null.
Also, it did not checked if _is{Boolean,Number,String} is function.
Fix SequencableCollection >> indexOf: family

It failed when JS null was present in collection.
Dictionary and HashedCollection under common base class
Update API-CHANGES.txt
Cleaned and restructured test for Dictionary and HashedCollection
Fixed HashedCollection >> removeKey:

Found by tests
Putting [ aBlock value ] in ifTrue:IfFalse: so the code is inlined
Merge pull request #758 from tomrake/base-path-validation

FileServer: added validation of --base-path; only existing directories should be allowed.
Merge pull request #794 from herby/assocative-collection-restructure

Assocative collection restructure
Merge pull request #791 from herby/indexof-fix

Indexof fix