savesym – Redefine symbols where names conflict

There are a num­ber of sym­bols (e.g., \Square) that are de­fined by sev­eral pack­ages. In or­der to type­set all the vari­ants in a doc­u­ment, we have to give the glyph a unique name. To do that, we de­fine \savesym­bol{XXX}, which re­names a sym­bol from \XXX to \origXXX, and \re­storesym­bols{yyy}{XXX}, which re­names \origXXX back to \XXX and de­fines a new com­mand, \yyyXXX, which cor­re­sponds to the most re­cently loaded ver­sion of \XXX.