mongoose: Fix for Linuxbrew.
mongoose: Fix for Linuxbrew.

mongoose was using Apple-only GCC flags and shared library naming
conventions.

Closes Linuxbrew/homebrew-core#79.

Closes Linuxbrew/homebrew-core#80.

Signed-off-by: Bob W. Hogg <c772a964fd55352a3510e5d535dd9ccc9ac30168@linux.com>

Linuxbrew/homebrew-core,forevergenin/homebrew-core,LinuxbrewTestBot/homebrew-core,LinuxbrewTestBot/homebrew-core,rwhogg/homebrew-core,maxim-belkin/homebrew-core,Linuxbrew/homebrew-core,rwhogg/homebrew-core,maxim-belkin/homebrew-core,forevergenin/homebrew-core