Stdlib: Removed all references to String constructors in nit stdlib and tests.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
nitg: Modified compilation routine to avoid use of String contructors

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
nitc: Removed use of String::with_native in nitc toolchain

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
c_src : Regenerated c_src to prevent use of String contructors

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
stdlib: Removed constructors from String

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>
Merge remote-tracking branch 'lucas/string_refactor'
string: more migration from String::from_cstring to NativeString::to_s

Signed-off-by: Jean Privat <jean@pryen.org>
tests: fix sav for error_needed_method.nit for String constructor migration

Signed-off-by: Jean Privat <jean@pryen.org>
add .mailcap because some people cannot set their Git identity correctly

Signed-off-by: Jean Privat <jean@pryen.org>
make: add more programs to doc/newmodel

Signed-off-by: Jean Privat <jean@pryen.org>
make: drop --public for doc/stdlib

Signed-off-by: Jean Privat <jean@pryen.org>