[Dovecot] Running 1.x and 2. x on same machine

[email builder]

Hello,

When building from source, is it possible to use "make install" to switch 
between version 1.x and 2.x on the same machine (just for testing)?  Do both 
versions install the same binaries?  Is configuration from 2.x backward 
compatible with 1.x? (so we can have the newest configuration files on our 
system without bothering to have a second set of 1.x config files)


Or instead should we be changing something like the installation and config 
directorie for one of the versions when we install it (how?).

Thanks for advice!!!!