Remove non compliant characters from gmt files

[mauromiguelm]

load(file="data-raw/extdata/gmt-all.rda",verbose=1)
Loading objects:
gmt.all
Warning message:
In load(file = "data-raw/extdata/gmt-all.rda", verbose = 1) :
input string 'RNASEQ:Amlexanox Ikk-Ɛ Tbk1 Nf-Κb GSE110206 1' cannot be translated to UTF-8, is it valid in 'CP1252'?

[mauromiguelm]

Another evidence that this might cause cause problems:

In load(file.path(temp_dir, "example-data.pgx")) :
  strings not representable in native encoding will be translated to UTF-8

I checked and it seems to be kappa, lambda... we might need to actively remove these characters.. @ivokwee?

[ivokwee]

Error or just warning? I only am afraid any links based on names might break. But otherwise all utf8 is perhaps good.

[mauromiguelm]

warning, but non compliant chars might cause NAs in some functions/plots/tables (as seen in wordcloud), so we could actively remove them from pathways.

Its a double edge knife, as greek letters look very good.