Improve overall plugins load performance

[outcoldman]

-antigen-parse-args is very expensive. Avoiding using it in internal calls improve overall performance.
Instead of using -antigen-parse-args just invoke functions with arguments in expected order.

I got 50% performance improvement.

[outcoldman]

Just a note, another way to get 50% improvement is to avoid using -antigen-parse-args at all. For example in my own .zshrc I specified function right after source ./antigen/antigen.zsh

    antigen-fbundle() {
        local loc=$1
        local url=${2:-$ANTIGEN_DEFAULT_REPO_URL}
        local make_local_clone=${3:-true}
        local btype=${4:-plugin}
        if $make_local_clone; then
            -antigen-ensure-repo $url
        fi

        _ANTIGEN_BUNDLE_RECORD="$_ANTIGEN_BUNDLE_RECORD\n$url $loc $btype"
        _ANTIGEN_BUNDLE_RECORD="$_ANTIGEN_BUNDLE_RECORD $make_local_clone"

        -antigen-load "$url" "$loc" "$make_local_clone"
    }

After that I use simplified syntax of

    antigen use oh-my-zsh

    antigen-fbundle plugins/bower
    #... other plugins

    # load from url
    antigen-fbundle / https://github.com/Tarrasch/zsh-autoenv.git

    # load from local locations (my own plugins)
    antigen-fbundle / ./plugins/aliases false

    # Load plugin
    antigen-fbundle powerlevel9k.zsh-theme https://github.com/bhilburn/powerlevel9k.git

    antigen apply

[desyncr]

I think they'll like to keep the old syntax. Regardless of that it's an alternative to the whole cache thing at #129. I'll try this later today.

[outcoldman]

@desyncr sure, it make sense, I don't want to change the syntax, this is why I just mentioned that it can be another way to improve performance.

This pull request is only about avoiding unnecessary using -antigen-parse-args in internal calls.

We definitely need to fix -antigen-parse-args, as it makes antigen load in 4x times slower. As a proposal we can make it less generic and work only for antigen bundle (including all other alternatives, like use or theme).

[forivall]

Just remember, desyncr isn't a contributor to antigen at all. I have a fixed version of antigen-parse-args in #132, but abandoned it because the maintainers seem to be absent, so I just switched to zgen.

[outcoldman]

@forivall looking on the history of commits it seems like that original maintainer @sharat87 is looking on patches once in a month, so we just need to have a little bit of patience. Could you reopen your pull request as it can be very useful for all antigen users.

[desyncr]

Thank you @outcoldman for these changes. It has been merged.