RFR: WIP repalce stdout by configurable object

[Jiří Vaněk]

Hello!

This is initial draft of stdout/-d unification, which will allow to use asmtools as universal library, where user will be able to set up his custom ToolInput, ToolOutput and ToolLog implementations

To do that, I should unify stdout and err of the tools. 
Disassembelrs are now logging to stderr and can print to stdout.
Assemblers are now logging to stderr and stdout and stdout only to -d dir

Main question before continuing - why are Assemblers  using both streams for logging? Can I unify them, so they log only to stderr?

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Commit messages:
 - WIP repalce stdout by configurable object

Changes: https://git.openjdk.org/asmtools/pull/38/files
 Webrev: https://webrevs.openjdk.org/?repo=asmtools&pr=38&range=00
  Stats: 193 lines in 9 files changed: 169 ins; 6 del; 18 mod
  Patch: https://git.openjdk.org/asmtools/pull/38.diff
  Fetch: git fetch https://git.openjdk.org/asmtools pull/38/head:pull/38

PR: https://git.openjdk.org/asmtools/pull/38