316 improve exception message (#318)

* improvement 316 add .idea directory to .gitignore

.idea directory should not be checked and is auto generated by the IDE.
So the directory should be ignored by git.

Signed-off-by: Simulant <nfaupel.dev@gmail.com>

* improvement 316 improve Exception message for missing constructor

when the default constructor is missing, the class name is contained in
the error message so the issue is easier to fix by the user.
Added a unit test to ensure the class name is contained in the message.

Signed-off-by: Simulant <nfaupel.dev@gmail.com>

* improvement 316 add missing java doc for parameter

Signed-off-by: Simulant <nfaupel.dev@gmail.com>

* bugfix 316 assert JsonbException instead of RuntimeException

Signed-off-by: Simulant <nfaupel.dev@gmail.com>
diff --git a/.gitignore b/.gitignore
index 22b2a1a..283e0e3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 /target/
 .classpath
 .project
+.idea/
 .settings/
 /.DS_Store