libxslt1-dev is used at least for asn1 and usrp. It breaks the build when in
check_install_additional_tools().
Move it to to check_install_oai_software()

uhd is not part of ubuntu standard repositories >= 14.04.
Move the removal of uhd in its own space and do not fail if it doesn't exists.

bladerf ppa don't publish packages for Ubuntu 16.04.
There are official packages for bladerf so we use these.

It breaks apt-get remove command

Add --disable-hardware-dependency flag to avoid hardware need when compiling OAI.
For the momment it avoids to flash bladeRF hardware

libpgm-dev will add the dependency on libpgm 5.2.0 or 5.1.0 automatically
according to the ubuntu version

liblas3gf have been replaced by libblas3 on 16.04
liblas3* will be pulled by libblas-dev, so we don't need to add it to package list

This package is needed for the command add-apt-repository

Thank to Thomas Laurent for refactorize get_distribution_released

build_helper exits early on error. compilations() tells where the
compilation logs can be found after compiling it. So in case of error, it
was never displayed.
Add a log info before compiling

Line 4 of *.h files depends on the directory containing openair;
get rid of it.