allow non-negative regression and no-intercept
bug fixes

Fixed small bug in parse.py, fixed bivariate point normal, had
ldsc.sumstats return intercept jackknife, too.
Merge branch 'no_intercept' into dev

Conflicts:
	ldsc.py
added --aggregate
Merge branch 'aggregate' into dev
added --betaprod-from-chisq
Merge branch 'betaprod' into dev
merge cts_bin into dev
added --print-snps plus more support for compressed text files
fixed the bug where --cts-bin threw a MemoryError when the SNP lists didn't match
tidied up chisq alleles code
added allele to file formats
added coefs to jackknife
added M_common as a default output for --l2 plus --M-file
added support for cts-bin and multiple things to bin on using pandas crosstab
added a --M-common flag to use .M_common by default (for estimating h2(5-50) )
adf
small bug fix in --l2
changed M common to M 5 50. more precise
ldsc --sumstats now removes zero-variance LD Score columns instead of throwing an error
--M-5-50 should work now