Build Tool: Homebrew/Linuxbrew formulae

[stephengaito]

Should we maintain Homebrew/Linuxbrew formulae?

[stephengaito]

Homebrew formulae are used by the MacOS community to install and/or build from sources the applications described by a formula.

Linuxbrew formulae do the same for Linux distributions.

[stephengaito]

Most importantly for us TravisCI (#4) makes use of the "official" Homebrew formula for pdf2htmlEX in order to build and test pdf2htmlEX on MacOS.

At the moment the "official" Homebrew formula for pdf2htmlEX is old, out of date, and broken, moreover it is still associated with @coolwanglu's old/archived coolwanglu/pdf2htmlEX project.

This needs to be fixed