Remove FMT dependency (#1472)

All occurrences of log() have been replaced with qDebug()

bonus meme: remove a bunch of std::string usages in the pubsub client

Fixes #1467

resources/licenses/fmt_bsd2.txt

@@ -1,23 +0,0 @@
-Copyright (c) 2012 - 2016, Victor Zverovich
-
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
-
-1. Redistributions of source code must retain the above copyright notice, this
-   list of conditions and the following disclaimer.
-2. Redistributions in binary form must reproduce the above copyright notice,
-   this list of conditions and the following disclaimer in the documentation
-   and/or other materials provided with the distribution.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
-SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

resources/resources_autogenerated.qrc

@@ -40,7 +40,6 @@
     <file>icon.png</file>
     <file>licenses/boost_boost.txt</file>
     <file>licenses/emoji-data-source.txt</file>
-    <file>licenses/fmt_bsd2.txt</file>
     <file>licenses/libcommuni_BSD3.txt</file>
     <file>licenses/openssl.txt</file>
     <file>licenses/pajlada_settings.txt</file>