task: calculate correct cmdline bytes

See merge request !2214

The previous patches to workaround
http://support.microsoft.com/kb/830473 drastically over estimated the
number of characters in commands by treating the repr() version of the
command array as a reasonable estimator of commandline length. This
caused commands attempt to write argsfiles before they should have.

The new calculation calculates the number characters in the command
array and adds the number of spaces that would be added by ' '.join(cmd)
this provides a much closer estimate of the commandline length.

This also limits the CLI-length on non windows platforms to 200kB. This
prevents us hitting the much larger argument limits on Linux/BSD/MacOS
platforms.

added stubs/ to lib search paths

See merge request !2213

javaw: add quiet=True to ant_globs to suppress warnings of globbing in build

See merge request !2212

Most of the ant_globs used are explicitly and knowingly on build directory
(ie. javadoc, jar re) so the warning is quite spurious. The only one that
may be in doubt is the source re one: I added also here because if you use
a code generator (ie. protoc) then it is also correct to glob on builds and
the warning is misleading.

Support multiple 'default_cmd'

See merge request !2211

buildcopy: Added warning if buildcopy is used without any files to copy

See merge request !2210

protoc: simplify the java generation also solving problems with .proto input files generated during build

See merge request !2209

protoc: simplify the java generation also solving problems with .proto input files generated during build

protoc: fix filename generation for .java

See merge request !2208

Fix all DeprecationWarning: invalid escape sequence

See merge request !2207

Signed-off-by: Mickaël Schoentgen <contact@tiger-222.fr>

Cython enhancements

See merge request !2196

Support for Fortran 2008 submodules.

See merge request !2205

Also build a main program that uses the parent module.

Its only built if gfortran is used at least with version 6.

Use correct variable in gccdeps config

See merge request !2203

protoc: fix included protoc search on nested wscripts

See merge request !2202

The global value gccdeps was appended to CFLAGS and CXXFLAGS instead of
the actual flags tested against the compiler.  This ignored
modifications to the GCCDEPS_FLAGS environment variable and complicated
adding support for additional compilers at the project level.

previously code was erroneously using tg.bld.path instead of tg.path
so for nested wscript calls the wrong directory was used in search.

added also better error handling with error message if an included
directory does not exist