[lmi] Automake and '.tpp' files

[Greg Chicares]

In 'Makefile.am' we say:

# headers: we need to include them or they wouldn't appear in the distribution
noinst_HEADERS = \
    about_dialog.hpp \
    account_value.hpp \
...

Shouldn't '.tpp' files be added to this list?

(They're like libstdc++'s 'basic_string.tcc' AIUI: source code
that contains an implementation, which might "normally" be
compiled as a translation-unit, but can otherwise be #included
as though it were a header. lmi's '.tpp' files are always
#included somewhere and never compiled separately.)