it might be nice if gettext will use the catalogs found in the local po/ dir so it wouldn't be necessary to call make install each time....Is there a way to do it?
If I am understanding your idea correctly, it sounds like gettext is able to do just that (i.e. change the translation path variable) if you follow the prescribed methods to set it up...
Translations should be stored in a path having a fixed structure.
First of all, we’ll have a root folder named to your taste (for
example “languages”). Inside it, we have to create a folder for every
targeted language whose name must comply to the ISO 3166 standard. So,
valid names for an Italian translation can be “it_IT” (Italian of
Italy), “it_CH” (Italian of Switzerland), “en_US” (English of USA),
and so on. Within the folder having the language code, we must have a
folder named “LC_MESSAGES” where, finally, we’ll store the translation
files.
From Here (there is a script example included in this link showing one method to perform this task)
Change "languages" in description above to "po", and that may do what you want?