CC-4956: Merge nginx + apache install full scripts

-install appropriate packages
CC-4970: Process return codes aren't "reaped" after exiting - Zombie processes are created.

-fixed
Merge branch '2.3.x' into devel
CC-4965: Fix airtime-silan import tool

-move to correct directory
CC-4965: Fix airtime-silan import tool

-various fixes
add airtime-silan to symlink to /usr/bin
CC-4965: Fix airtime-silan import tool

-prevent zombie processes
Merge branch '2.3.x' into devel
prevent creation of Zombie processes when running lsof
Merge branch '2.3.x' into devel
make sure path names are quoted when passing to lsof
undo - make sure path names are quoted when passing to lsof
CC-4975: airtime-silan cmd error

-fixed
CC-4888: Add unofficial support for AAC plugin

-fixed
potential future optimization by using -b silan option

-in the future this -b should be quicker for silan
less verbose logging
CC-4974: Watchdog for ensuring Liquidsoap does not consume more than 1GB of memory

-changed to 600MB for now. May lower even more later
CC-4980: Create graphic with 4 switches for Airtime Dashboard
Revert "CC-4980: Create graphic with 4 switches for Airtime Dashboard"

This reverts commit baf693d1a97ed97f59105e3f580b12a1314c77c9.
minor refactor of LS code