ICU_LINK option does not work anymore

[nenomius]

ICU_LINK option does not work now, because boost.regex errors build if sees it now.
See boostorg/regex@fc4dc17 and boostorg/regex#89

I would suggest moving ICU finding/configuration into shared file and using it from there like its done for zlib, bzip2, etc, and not doing the same thing in different ways.

@jzmaddock

[leha-bot]

Finally I can build boost locale in Android NDK without dirty hacks 🥳

[Flamefire]

@leha-bot Does this mean you tested #120 already and can confirm it works for you?