build: compile with -Xlint:all
Would like to eventually enable -Werror; left as comment since it'll
need some non-trivial revamping of the resolver code and the generated
protobuf code uses the deprecated valueOf function.
<source>${jdk.version}</source>
<target>${jdk.version}</target>
<encoding>UTF-8</encoding>
+ <compilerArgs>
+ <arg>-Xlint:all</arg>
+ <!-- TODO <arg>-Werror</arg> -->
+ </compilerArgs>
</configuration>
</plugin>
<plugin>
