Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

 templates/oscar#	gelöscht:       searx/static/themes/oscar/fonts/glyphicons-halflings-regular.ttf

Strings like::

    'Query in the page\'s title'

are hard to read / remove escape sequence by using double quotation marks for
strings ::

    "Query in the page's title"

BTW: remove a leading dot in the simple theme [1].

[1] https://github.com/searxng/searxng/pull/485/files/80fb77476fad4b229418c530f3ffda67f357a15a#r756112716

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

In the templates and the /config (JSON) the usage of the 'brand.*' name
space is replaced by 'searx.get_setting' function.

- new_issue_url          --> get_setting('brand.new_issue_url')
- brand.GIT_URL          --> get_setting('brand.git_url')
- brand.PUBLIC_INSTANCES --> get_setting('brand.public_instances')
- brand.DOCS_URL         --> get_setting('brand.docs_url')
- brand.ISSUE_URL        --> get_setting('brand.issue_url')
- brand.CONTACT_URL      --> get_setting('general.contact_url', '')

The macro 'new_issue' from searx/templates/*/messages/no_results.html
is now imported with context::

    {% from '__common__/new_issue.html' import new_issue with context %}

To get *public instances URL* from context's 'get_setting()' function::

    get_setting('brand.public_instances','')

Macro's prototype does no longer need the 'new_issue_url' argument and has been
changed to::

    macro new_issue(engine_name, engine_reliability)

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

closes: #2383

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>