Rework activate to support more configurations

[shadowspawn]

Pull Request

Ideally copying the files during install would be a simpe command. Not so in practice! The original two folder copies have grown over the years to cope with special cases and add functionality.

Problem

• using multiple code paths depending on install
  • if top level target folder is symlink, use find and cp
  • if preserving npm, use rsync
  • else (normal) use cp
• requiring rsync for --preserve
• not supporting OS with symlink for /usr/local/share/man, such as archinux (Error when copying .../share/man #100)
• installing global packages when using n exec would pollute cache and affect later installs

Solution

Use hand-crafted code for install using just find and cp. Use same code independent of symlinks.

Only copy known binaries and expected node_modules to mitigate cache pollution (n exec).

A downside is slightly less robust about future changes to what is contained in archive.

ChangeLog

• support installs where /usr/local/share/man is a symlink (such as archlinux)
• remove requirement for rsync for --preserve
• avoid pollution if user installs global packages when using n exec