Inconsistent management of folder name starting by "..."

reactos-bootcd-0.4.16-dev-1007-g2e85425-x86-gcc-lin-dbg

• Attempt to create a folder names "...xxx" in explorer
• Rejected (invalid name)
• Attempt to create a folder names "...xxx" in mkdir
• Accepted, then displayed in Explorer
• if a "trailing" dot is used (eg: "test."), the dot is trimmed by both explorer and mkdir

This leads to CORE-20129