Collect contribution ideas

[pavelkumbrasev]

Description

This patch provides a list of tasks that the community can help us with.

[pavelkumbrasev]

I did not cover each and every task that are available for contribution in this initial commits. Please, @kboyarinov @aleksei-fedotov @isaevil @akukanov @vossmjp feel free to add more ideas as part of this PR.

[pavelkumbrasev]

Idea: improve proxy tasks clean-up mechanism

[phprus]

My PRs: #714 (Workaround for issue #558, Assertion isMallocInitialized() failed) #1114 (Use gcc visibility attribute)