Installation path can now be changed in a subsequent install,
without uninstalling and logging out.
The default value of the installation path is set to
IDF_TOOLS_PATH environment variable, if it was already set by the
previous installation, or by the user.
Closes https://github.com/espressif/esp-idf/issues/3806
Uninstaller is still unsigned, as currently building and signing in 'wine'
and running Linux osslsigncode inside Inno Setup inside wine is awkward.
Closes https://github.com/espressif/esp-idf/issues/1909
TW20810
These versions of conf/mconf are forked from the upstream, and the CMake system allows mconf-idf to
be installed externally on the path. So the best option is to rename.
Includes changes to Windows installer for v1.1
