g3log: add version 2.1

[toge]

Specify library name and version: g3log/*

• add version 2.1
• add C++17 mode for g3log>=2.0
• use add_subdirectory in test_v1_package

---

• I've read the contributing guidelines.
• I've followed the PEP8 style guides for Python code in the recipes.
• I've used the latest Conan client version.
• I've tried at least one configuration locally with the conan-center hook activated.

[github-actions]

Hooks produced the following warnings for commit e322539

g3log/1.3.4

post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library './lib/libg3log.so' links to system library 'm' but it is not in cpp_info.system_libs.
post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library '.\bin\g3log.dll' links to system library 'dbghelp' but it is not in cpp_info.system_libs.

g3log/1.3.3

post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library './lib/libg3logger.so' links to system library 'm' but it is not in cpp_info.system_libs.
post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library '.\bin\g3logger.dll' links to system library 'dbghelp' but it is not in cpp_info.system_libs.

g3log/1.3.2

post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library './lib/libg3logger.so' links to system library 'rt' but it is not in cpp_info.system_libs.
post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library './lib/libg3logger.so' links to system library 'm' but it is not in cpp_info.system_libs.
post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library '.\bin\g3logger.dll' links to system library 'dbghelp' but it is not in cpp_info.system_libs.

g3log/1.3.2-86

post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library './lib/libg3logger.so' links to system library 'm' but it is not in cpp_info.system_libs.
post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library '.\bin\g3logger.dll' links to system library 'dbghelp' but it is not in cpp_info.system_libs.

g3log/2.1

post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library './lib/libg3log.so' links to system library 'm' but it is not in cpp_info.system_libs.
post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library '.\bin\g3log.dll' links to system library 'dbghelp' but it is not in cpp_info.system_libs.

[uilianries]

LGTM

[github-actions]

Hooks produced the following warnings for commit f2169b5

g3log/1.3.2

post_package(): WARN: [MISSING SYSTEM LIBS (KB-H043)] Library './lib/libg3logger.so' links to system library 'rt' but it is not in cpp_info.system_libs.

[prince-chrismc]

Super tiny nit to bot confuse consumers

[conan-center-bot]

Conan v1 pipeline

All green in build 7 (14f970ecba7d99098584b0fa45ae6dc39d89a691):

• g3log/1.3.4@:
  All packages built successfully! (All logs)

• g3log/1.3.2-86@:
  All packages built successfully! (All logs)

• g3log/1.3.3@:
  All packages built successfully! (All logs)

• g3log/1.3.2@:
  All packages built successfully! (All logs)

• g3log/2.1@:
  All packages built successfully! (All logs)