This is to set CMDER_START to home when no directory is given.
This is to ensure it is set even though it will default to the home
directory anyway.
It’ll allow users to use CMDER_START even if started without a path.
The new system works by setting "CMDER_START" if a cmder.exe gets a
startup path. The rest is then implemented in the profile.ps1 and init.bat.
The new system works as follows:
1.If a startup path is given, cmder.exe sets this as `CMDER_START` and the
startup scripts change to that directory.
2.If the usere sets a `CMDER_START` environment variable and this is not
overwritten by cmder.exe, this variable is taken as the startup
directory by the startup scripts.
3.If not such path is give, the conemu startup dirs is the winner, as the
startup scripts don't change anything.
Existing code registered right-click only for blank areas of the
Explorer window. This change adds a menu item for right-clicking on a
folder in the file list.
Also adds the program's icon to help find it in a crowded context menu.
