text/template: handle panic values that are not errors.
text/template: handle panic values that are not errors.

The recover code assumes that the panic() argument was
an error, but it is usually a simple string.
Fixes issue 2663.

R=golang-dev, r, r, gri
CC=golang-dev, remy
http://codereview.appspot.com/5527046

Committer: Rob Pike <4dc7c9ec434ed06502767136789763ec11d2c4b7@golang.org>

Triskite/willstone-goclone,bryanxu/go-zh,mhennings/marcohennings-go,d0f/go-zh,d0f/go-zh,d0f/go-zh,Triskite/willstone-goclone,scirelli/scirelli-go,glycerine/jeaten-go-arrayof-structof,rflanagan/reginaldflanagan-project1,rdp/rogerpack2005-golang,Triskite/willstone-goclone,Triskite/willstone-goclone,sanjosh/sanjos100-tipc,bryanxu/go-zh,rdp/rogerpack2005-golang,bryanxu/go-zh,bryanxu/go-zh,d0f/go-zh,glycerine/jeaten-go-arrayof-structof,webfd/go-zh,mhennings/marcohennings-go,sanjosh/sanjos100-tipc,mhennings/marcohennings-go,sanjosh/sanjos100-tipc,rflanagan/reginaldflanagan-project1,webfd/go-zh,d0f/go-zh,bryanxu/go-zh,sanjosh/sanjos100-tipc,mhennings/marcohennings-go,bryanxu/go-zh,glycerine/jeaten-go-arrayof-structof,scirelli/scirelli-go,glycerine/jeaten-go-arrayof-structof,Triskite/willstone-goclone,rdp/rogerpack2005-golang,d0f/go-zh,rdp/rogerpack2005-golang,webfd/go-zh,mhennings/marcohennings-go,glycerine/jeaten-go-arrayof-structof,scirelli/scirelli-go,rflanagan/reginaldflanagan-project1,rdp/rogerpack2005-golang,scirelli/scirelli-go,sanjosh/sanjos100-tipc,mhennings/marcohennings-go,rflanagan/reginaldflanagan-project1,glycerine/jeaten-go-arrayof-structof,scirelli/scirelli-go,webfd/go-zh,glycerine/jeaten-go-arrayof-structof,rflanagan/reginaldflanagan-project1,d0f/go-zh,sanjosh/sanjos100-tipc,mhennings/marcohennings-go,rdp/rogerpack2005-golang,sanjosh/sanjos100-tipc,rflanagan/reginaldflanagan-project1,mhennings/marcohennings-go,webfd/go-zh,scirelli/scirelli-go,rflanagan/reginaldflanagan-project1,Triskite/willstone-goclone,Triskite/willstone-goclone,bryanxu/go-zh,rdp/rogerpack2005-golang,webfd/go-zh,webfd/go-zh,Triskite/willstone-goclone,rdp/rogerpack2005-golang,bryanxu/go-zh,webfd/go-zh,sanjosh/sanjos100-tipc,glycerine/jeaten-go-arrayof-structof,scirelli/scirelli-go,scirelli/scirelli-go,d0f/go-zh,rflanagan/reginaldflanagan-project1