"install boost @1.52.0" should not install a later version without comment

[dave@…]

Z% sudo /opt/local/bin/port install boost @1.52.0 
--->  Computing dependencies for boost
--->  Fetching archive for boost
--->  Attempting to fetch boost-1.53.0_1+no_single+no_static+python27.darwin_12.x86_64.tbz2 from http://packages.macports.org/boost
--->  Attempting to fetch boost-1.53.0_1+no_single+no_static+python27.darwin_12.x86_64.tbz2.rmd160 from http://packages.macports.org/boost
--->  Installing boost @1.53.0_1+no_single+no_static+python27
--->  Activating boost @1.53.0_1+no_single+no_static+python27
--->  Cleaning boost
--->  Updating database of binaries: 100.0%
--->  Scanning binaries for linking errors: 100.0%
--->  No broken files found.
Z%

I asked for @1.52.0, a perfectly reasonable thing to do, but port instead installs 1.53.0. This is wrong. Port should install the version I asked for, or if it can't or won't, then it should complain and exit nonzero. Until such time as port would be so kind as to actually install an asked-for old version, it could help by printing out the svn command I would need to use to get the old version, or better yet, a shell command that gets it and puts it in the right place.

[ryandesign (Ryan Carsten Schmidt)]

Duplicate of #24520.