Update https://github.com/gohugoio/hugo in repo_dependencies.yml from v0.49 to v0.51

[dependencies]

Dependencies.io has updated https://github.com/gohugoio/hugo (a git dependency in repo_dependencies.yml) from "v0.49" to "v0.51".

v0.51

Hugo reached 30 000 stars on GitHub this week, which is a good occasion to do a follow-up release of the great Hugo 0.50. This is mostly a bug fix release, but it also adds some useful new functionality, two examples are the new template funcs complement and symdiff. This release also continues the work on improving Hugo's error messages. And with .Position now available on shortcodes, you can also improve your own error messages inside your custom shortcodes:

{{ with .Get "name" }}
{{ else }}
{{ errorf "missing value for param 'name': %s" .Position }}
{{ end }}

When the above fails, you will see an ERROR log similar to the below:

ERROR 2018/11/07 10:05:55 missing value for param name: "/sites/hugoDocs/content/en/variables/shortcodes.md:32:1"

This release represents 31 contributions by 5 contributors to the main Hugo code base.
bep leads the Hugo development with a significant amount of contributions, but also a big shoutout to krisbudhram, LorenzCK, and coliff for their ongoing contributions.
And a big thanks to digitalcraftsman and onedrawingperday for their relentless work on keeping the themes site in pristine condition and to kaushalmodi for his great work on the documentation site.

Many have also been busy writing and fixing the documentation in hugoDocs,
which has received 6 contributions by 5 contributors. A special thanks to ikemo3, maiki, morya, and regisphilibert for their work on the documentation site.

Hugo now has:

• 30095+ stars
• 441+ contributors
• 276+ themes

Notes

• Remove deprecated useModTimeAsFallback 0bc4b024 bep
• Bump to ERROR for the deprecated Pages.Sort faeb55c1 bep
• Deprecate .Site.Ref and .Site.RelRef 6c6a6c87 bep #5386

Enhancements

Templates

• Properly handle pointer types in complement/symdiff 79a06aa4 bep
• Add collections.SymDiff 488776b6 bep #5410
• Add collections.Complement 42d8dfc8 bep #5400

Core

• Improve error message on duplicate menu items 3a44920e bep
• Add .Position to shortcode 33a7b36f bep #5371

Other

• Document shortcode error handling e456e34b bep
• Document symdiff 5d14d04a bep
• Document complement ddcb4028 bep
• Update minify d212f609 bep
• Re-generate CLI docs 2998fa0c bep
• Add --minify to hugo server 5b1edd28 bep
• Make WARN the new default log log level 4b7d3e57 bep #5203
• Regenerate the docs helper 486bc46a bep
• Skip watcher event files if matched in ignoreFiles f8446188 krisbudhram
• Update Chroma d523aa4b bep #5392
• Add file (line/col) info to ref/relref errors 1d18eb05 bep #5371
• Improve log color regexp d3a98325 bep
• Correct minor typo (#5372) e65268f2 coliff

Fixes

Templates

• Fix the docshelper 61f210dd bep
• Fix BOM issue in templates 3a786a24 bep #4895

Output

• Fix ANSI character output regression on Windows b8725f51 LorenzCK #5377

Core

• Fix changing paginators in lazy render b8b8436f bep #5406
• Fix REF_NOT_FOUND logging to include page path 6180c85f bep #5371
• Fix broken manual summary handling b2a676f5 bep #5381
• Fix deadlock when content building times out 729593c8 bep #5375

Other

• Fix spelling 47506d16 qeesung
• Fix shortcode directly following a shortcode delimiter d16a7a33 bep #5402
• Fix recently broken error template 2bd9d909 bep