[UWS,TAP] Set UTF-8 as default character encoding for all HTTP response.

src/tap/ADQLExecutor.java

src/tap/error/DefaultTAPErrorWriter.java

src/tap/metadata/TAPMetadata.java

src/tap/resource/Availability.java

src/tap/resource/Capabilities.java

src/tap/resource/HomePage.java

src/tap/resource/TAP.java

src/uws/UWSToolBox.java

src/uws/service/UWSService.java

src/uws/service/UWSServlet.java

src/uws/service/actions/AddJob.java

src/uws/service/actions/DestroyJob.java

src/uws/service/actions/GetJobParam.java

src/uws/service/actions/JobSummary.java

src/uws/service/actions/ListJobs.java

src/uws/service/actions/SetJobParam.java

src/uws/service/actions/SetUWSParameter.java

src/uws/service/actions/ShowHomePage.java

src/uws/service/error/DefaultUWSErrorWriter.java