Worker dependencies

Rewritten-docs.md

@@ -2829,7 +2829,32 @@ comply most of possible use cases.
 
 ### Additional libraries
 
-@todo: libcurl, spdlog, boost, yaml-cpp, libarchive, cppzmq
+Worker implementation depends on several open-source C and C++ libraries. All of
+them are multi-platform, so both Linux and Windows builds are possible.
+
+- **libcurl** -- Libcurl is used for all HTTP communication, that is downloading
+  and uploading files. Due to lack of documentation of all C++ bindings the
+  plain C API is used.
+- **libarchive** -- Libarchive is ised for compressing and extracting archives.
+  Actual supported formats depends on installed packages on target system, but
+  at least ZIP and TAR.GZ should be available.
+- **cppzmq** -- Cppzmq is a simple C++ wrapper for core ZeroMQ C API. It
+  basicaly contains only one header file, but its API fits into worker's object
+  architecture.
+- **spdlog** -- Spdlog is small, fast and modern logging library. It is used for
+  all of the logging, both system and job logs. It is highly customizable and
+  configurable from worker's configuration.
+- **yaml-cpp** -- Yaml-cpp is used for parsing and creating text files in YAML
+  format. That includes worker's configuration, job's configuration and job's
+  results.
+- **boost-filesystem** -- Boost filesystem is used for multi-platform
+  manipulation with files and directories. However, these operations will be
+  included in future releases of C++ standard, so this dependency may be
+  removed in the future.
+- **boost-program_options** -- Boost program options is used for multi-platform
+  parsing of command line positional arguments. It is not necessary to use it,
+  similar functionality can be implemented be ourselves, but this well known
+  library is effortless to use.
 
 ## Monitor