_strip_ExtJS4_nw.sh: cleanup `ext-all-debug.js` for production

$ sh ../../_strip_ExtJS4_nw.sh

PWD:    '/d/supro/git-repo/supro'
OUTPUT: '../../../extjs-4.2/ext-all-nw.js'
EXTJS4: '../../../#_projects/extjs4/extjs'
HEAD:   'a674f64777f471e49493b1c492c4626cdf4ac800'

size diff: 1447 kibytes

Signed-off-by: Oleg Verych <olecom@gmail.com>