user/zola: Bump to 0.8.0; add docs and completions

This may or may not fix pmmx. I don't understand the error there, as the variable is definitely defined: https://github.com/rust-lang-deprecated/time/blob/master/src/lib.rs#L66

See merge request !258

Rust utils (ripgrep, xsv, zola)

Some new rust utilities that exercise @sysvinit's cargo-fu

See merge request !250

Bump poppler and rebuild rdeps

* `poppler` was bumped from `0.74.0` to `0.77.0`. Due to a soname bump the reverse dependencies were rebuilt:

    ```
    atril
    calligra
    cups-filters
    evince
    tumbler
    ```
    Notably absent is `libreoffice` which is being upgraded separately.

* Likewise with `poppler-qt5`. There was not a soname bump here, but [one of the intermediate versions still appears to have had some ABI changes](https://abi-laboratory.pro/index.php?view=objects_report&l=poppler&v1=0.76.0&v2=0.76.1), so these packages were rebuilt as well:

    ```
    kfilemetadata
    krita
    okular
    qpdfview
    tellico
    ```
* `exiv2` was bumped from `0.26` to `0.27.1`, which entailed a soname bump. These packages were rebuilt (there is some overlap here with the above, thus inclusion in this MR):

    ```
    gwenview
    kfilemetadata
    kphotoalbum
    krita
    libkexiv2
    ```

See merge request !255