Libzip wrapper fixes and improvements

[Anvell]

As discussed here: https://forum.nim-lang.org/t/3077

Added:

• Replacing files in zip
• Renaming/removing
• Ability to switch between deflate/store method
• Fixed path issues on Windows
• static link by default

Note: not compatible with old libzip_all.c

[Araq]

Does it work on Windows?

[Anvell]

Yes, I'm on Win only. Though if someone is using MSVC instead of MinGW it would require other linking directives?

[dom96]

It seems fishy that GitHub thinks you've modified the whole file when the contents are the same...

I'm guessing you changed the newline characters for these files? You need to fix that.

[Anvell]

Sure, done :)

[iffy]

What's the status on this PR? I'm new to nim and think I want a statically linked libzip. (I could be convinced otherwise, of course)

[Araq]

This PR needs to keep the possibility to link against the DLL/lib.so file.

[brentp]

it would be useful for me to have static linking to a more recent libzip. How having:

when defined(zipSharedLib):
  when defined(macosx):
    {.pragma: mydll, dynlib: "libzip(|2|4).dylib".}
  else:
    {.pragma: mydll, dynlib: "libzip(|2).so(|.4|.2|.1|.0)".}
else:
  {.passl: "-static".}
  {.passl: "-lzip".}
  {.passl: "-lz".}

as the (additional) change?

[Araq]

@brentp Sounds good to me.

[brentp]

@Anvell will you make those changes? Or shall I make a new PR from your branch?

[Anvell]

Feel free to make new PR, I have not worked with Nim for some time :)