jooby-run: improve restart process (less memory/fast)

[jknack]

The work done by @agentgt at #2583 works OK but left out of queue the compilation process. On small project there is no difference but on medium/large code base one multiple file changes are detected multiples restart are fired but also waits on compiler to finish.

Today:

• file 1 changed/file 2 changed -> compile (probably fired twice bc file 1 and file 2) -> queue file1 and file 2 -> application restart

After:

• file 1 changed/file 2 changed -> queue file 1/ queue file 2 -> compile once -> application restart