Do not return any filesystem when there are no settings.
This is a fix of issue #52026.

Permit to return null from FSInfo.getFileSystem(). When null is returned,
that FSInfo is considered not to be valid and is discarded.
This is necessary for the fix of issue #52026.

fixed issue with NONINTERACTIVE

incremented spec version

Added code that handles a special case in the LIST_CMD.

Added supportsAdvancedMode="true" to Local.list, Local.resolved, Local.cleanup, Local.switch, Local.propdelete, Local.Remote.blame, Remote.log, Remote.cat
Added refreshParentFolder="true" to local.mkdir, local.revert, local.move, local.copy instead of refreshCurrentFolder="true". Refresh works properly for files and dirs.
Added runOnMultipleFiles="true" to local.list (remote.list was ok)
Added message field to remote.move
Added more status indicators
Added special case to SubversionListCommand.outputData that fixes the regular expression output in the case where revision numbers are missing from the line.
Added GENERIC_STATUS_* and ICONS_FOR_FILE_STATUSES
Fixed PWORD variable so that it doesn't return garbage when no password is given.
Fixed remote.move command. The inputDescripter was missing a ")" and caused an exception.
Fixed LIST_CMD regular expression to properly parse "?" in the status field and "-" in the working copy revision field for added files.
Changed URL usage so that it's always quoted (URL, QURL, URL_D, QURL_D, QURL_U)
Changed QUIET variables to properly use QUIET_U and QUIET_G
Changed NONINTERACTIVE_U to NONINTERACTIVE_D where it was used as the default value in a dialog
Changed some command names to "*_LOCAL" and "*_REMOTE"
Changed message field to a non expert (non advanced) field for applicable remote commands b/c they were being run without any request for a message.
Changed labels and accessibility descriptions in CONFIG_INPUT_DESCRIPTOR for username, password, quiet, no-auth-cache, encoding
Changed the global no-auth-cache to default to true
Changed local.diff to prompt for old revision
Changed remote.diff to prompt for old and new revisions
Changed diff to properly support first two forms but not the third (3 is short hand for 2) @rev not supported
Removed unecessary regex from status along with the indexes
Removed refreshParentFolder="true" for remote.move since it didn't make since. User must run update to see the changes.
Removed regex from refresh command since it is "inherited" from the LIST_CMD
Plus misc improvements

Added more indicators.

Merge the two combo boxes together into a single tree-style combo box.

Finally killing libs/regexp.

Projectizing the lexer/editorbridge/calc example.