Get a working directory for i2p.
For the location, first try the system property i2p.dir.config
Next try $HOME/.i2p on linux or %APPDATA%\I2P on Windows.
If the dir exists, return it.
Otherwise, attempt to create it, and copy files from the base directory.
To successfully copy, the base install dir must be the system property i2p.dir.base
or else must be in $CWD.
If I2P was run from the install directory in the past,
and migrateOldData = true, copy the
necessary data files (except i2psnark/) over to the new working directory.
Otherwise, just copy over a limited number of files over.
Do not ever copy or move the old i2psnark/ directory, as if the
old and new locations are on different file systems, this could
be quite slow.
Modify some files while copying, see methods below.
After migration, the router will run using the new directory.
The wrapper, however, must be stopped and restarted from the new script - until then,
it will continue to write to wrapper.log* in the old directory.
public static String getWorkingDir(Properties envProps,
Only call this once on router invocation.
Caller should store the return value for future reference.
This also redirects stdout and stderr to a wrapper.log file if there is no wrapper present,
unless system property I2P_DISABLE_OUTPUT_OVERRIDE is set.
migrateOldConfig - whether to copy all data over from an existing install