Code:
> cat file3
<voms.db.type
value="changeme"/>
<voms.db.host
value="changeme"/>
<voms.admin.smtp.host
value="changeme"/>
<voms.mysql.admin.password
value="changeme"/>
<glite.installer.verbose
value="true"/>
> sed "s/>/>~/g" file3 | tr -d "[ ][\n]" | tr "~" "\n"
<voms.db.typevalue="changeme"/>
<voms.db.hostvalue="changeme"/>
<voms.admin.smtp.hostvalue="changeme"/>
<voms.mysql.admin.passwordvalue="changeme"/>
<glite.installer.verbosevalue="true"/>
>
Explained...
substitute > with >~ so can easily find end-of-lines
delete space and new-line characters
(note, the sample I copied/pasted had extra spaces after data in some lines)
then substitute new-lines for the ~ I used as marker in first step
Expect someone to offer an easier solution, but this is one approach