Backported the minimal set of changes required to build 2.1 with GCC
8. The format-truncation and format-overflow warnings are disabled instead
of fixed in 2.1 to remove duplication of effort that was already done in
2.2 (the commit doesn't cherry-pick cleanly).
If the avrorouter is being build and the required libraries are not found,
the configuration process should fail. Adding the command to bypass this
into the error message should make it easier to disable this part if it is
not needed.
The parser checks whether the FIRST or AFTER keywords are used and, if
AFTER is used, extracts the relevant column name.
Added a test case that checks that the parsing works and detects the
correct column names.
