Lock: Add lock mechanism with array of input sigs

[Catya3]

Name TBD

This is used when you have multiple sig and you want to wait on all of them to do something. A very common scenario.

:start -> (0 -> polyLock:data)
0 -> println -> polyLock:sig[0]
1 -> println -> polyLock:sig[1]
2 -> println -> polyLock:sig[2]
polyLock -> :stop

[emil14]

A very common scenario

1. If that's the case, please add some examples :)
2. What do you think about updating Lock instead of adding new component?
3. About having this in a separate package e.g. sync.PolyLock?
4. About name like WaitGroup? People familiar with go immediately understand what is this. Especially if it's gonna be sync.WaitGroup

[emil14]

We decided to create sync package

[emil14]

BTW other names could be LockAll or LockMany