Pass location with errors in codegen to have markers in editors in Eclipse

Fixes issue #110
Merge pull request #149 from tbroyer/codegen-error-markers

Pass location with errors in codegen to have markers in editors in Eclipse
Use getCanonicalName rather than getName when emitting source, by principle.

While we only call getName() on top-level class, getCanonicalName is more
accurate when we want the source name rather than the binary name.
Remove redundant code re. finding no-args constructors.
Report error at codegen when child module is missing @Module annotation

It previously failed with an NPE.
Also adds a test for the reflective backend.
Merge pull request #150 from tbroyer/fix-npe-in-fullgraphprocessor

Report error at codegen when child module is missing @Module annotation
Fix integration test: add missing invoker.properties
Nit-picking, following IntelliJ IDEA suggestions.
Merge pull request #152 from tbroyer/fix-it

Fix integration test: add missing invoker.properties
Merge pull request #151 from tbroyer/nitpicking

Nitpicking / code cleanup
Use standalone version of 'JavaWriter'.

Available at http://github.com/square/javawriter/
Merge pull request #153 from square/jw/javawriter

Use standalone version of 'JavaWriter'.
Add link to QCon talk.

Also change the link colors to something a bit less awful.
Merge pull request #155 from square/jw/qcon

Add link to QCon talk.
Upgrade to JavaWriter 1.0.2. Drop now-duplicated method.
Merge pull request #156 from square/jw/one-dot-oh-dot-two

Upgrade to JavaWriter 1.0.2. Drop now-duplicated method.